Application of Localization, Positioning and Navigation Systems for Robotic Enabled Mobile Products

ABSTRACT

A robotic cleaner includes a cleaning assembly for cleaning a surface and a main robot body. The main robot body houses a drive system to cause movement of the robotic cleaner and a microcontroller to control the movement of the robotic cleaner. The cleaning assembly is located in front of the drive system and a width of the cleaning assembly is greater than a width of the main robot body. A robotic cleaning system includes a main robot body and a plurality of cleaning assemblies for cleaning a surface. The main robot body houses a drive system to cause movement of the robotic cleaner and a microcontroller to control the movement of the robotic cleaner. The cleaning assembly is located in front of the drive system and each of the cleaning assemblies is detachable from the main robot body and each of the cleaning assemblies has a unique cleaning function.

RELATED APPLICATION

This application claims priority to provisional application Ser. No.61/125,684, filed Apr. 24, 2008, entitled “Application of Localization,Positioning & Navigation Systems for Robotic Enabled Mobile Products”

BACKGROUND OF THE INVENTION

At their core, robotic floor cleaners integrate at least two primaryfunctional systems: (1) a cleaning mechanism, which cleans the floor inthe area where it is placed or moved across, and (2) a mobile roboticplatform, which autonomously moves the cleaning mechanism across thefloor to different places. Both of these functional systems must workadequately for the robot to be effective at cleaning.

While both functional systems set requirements and constraints on thedesign of the overall robot, the challenge of developing a mobilerobotic platform that can autonomously move around in nearly an infinitevariety of highly unstructured environments (e.g. people's homes) tendsto be the dominant consideration and has had a significant effect on thedesign of home cleaning robots to this date.

In terms of robotic floor cleaners currently available, the constraintis so great that the vast majority of units manufactured to this datefollow the same general form factor. The mobile robot platform iscontained within a shell having a circular base, similar in shape tohockey puck but much larger than that. Two independently controlleddrive wheels are set within the circle on opposite sides of the robot.The wheels are along the center axis of the circle bisecting the forwardand rear halves of the robot.

In addition, the mobile robot platform has one or more caster wheels forsupport at the forward and/or rear ends of the robot to provide lateralstability and act as part of the robot's suspension. Some designs useonly one caster in the front, but distribute the weight to be heavier inthe front to keep the robot from tipping backward.

The circular shape makes the robot much easier to navigate aroundobstacles and along walls. With the wheels fully nested within thecircle and placed along the center axis, the robot can effectively turnin place to change its heading without the sides of the robot hittingany exterior obstacles.

The cleaning robot design also allows contact sensors (e.g., located ona bumper) and proximity sensors (IR sensors) to be placed along theouter sides of the robot to detect obstacles and follow along walls andfurniture. In some designs, the bumper may extend outside the boundaryof the circular base as a means for feeling for walls and obstacles asthe robot turns. The current cleaning robot design also includes dropsensors beneath the robot for detecting drop offs in the floor beforethe robot drives over a hazard.

Examples following this design framework include robot vacuum cleanerssuch as Eletrolux®'s Trilobite®, iRobot®'s Roomba®, Yujin's iClebo,Samsung®'s Hauzen® robots, as well as floor scrubbing robots such asiRobot®'s Scooba® robot. The downside of the presently availablesolution for the mobile robotic platform is that the currentconfigurations limit the size, reach and effectiveness of the cleaningmechanism.

In the typical robotic floor cleaner approach, the primary cleaningmechanism (such as a vacuum or beater brush) is designed to fit entirelywithin the footprint of mobile robot platform. Given that the dominantplatform shape is circular for most robotic floor cleaners, the cleaningapparatus necessarily has be narrower than the robot itself, cover asmaller area of the floor relative to the size of the overall robot, andis not able to directly reach all the way to walls and into corners.This is particularly sub-optimal for cleaning mechanisms such asvacuums, brushes and other devices, which tend to be rectangular inshape and don't match well with the geometry of a circle.

To compensate for this limitation, designers of the robotic cleanershave added an “edge cleaning” feature in the form of a small sidespinning brush that reaches out from the side of the robot. The smallside spinning brush attempts to draw debris into the path of thecleaning apparatus, although this has limited effectiveness and oftenneeds to be replaced due to wear.

The typical placement of the wheels and casters to support a circularrobot platform places additional constraints on the cleaning mechanism.As one limitation, the cleaning mechanism can not extend to an areawhere there is a wheel or caster, further limiting its size andconfiguration. Additionally, the robot usually requires a more complexsuspension system to keep the cleaning mechanism in contact with thefloor to be effective in cleaning, while at the same time maintainprimary contact between the floor and the wheels and casters in orderfor the robot to be effective in driving over the floor surface and oversmall obstacles.

A number of variations on the typical robot floor cleaner configurationhave been proposed in an attempt to reduce the constraints on thecleaning apparatus and increase its effectiveness, but these solutionsstill prioritize the mobility and function of the robotic platform overthe function of the cleaning mechanism itself.

Products with a non-circular shape, such as The Shaper Image®'s ovalshaped eVac™ robotic vacuum, have been introduced to the market. In thisoval-shaped robotic vacuum, the front leading edge was flattened toallow the vacuum to reach parallel to the wall in front of the robot,but the cleaning mechanism was still nested within the shell of thecleaning robot and did not extend to the sides.

Other robotic cleaner designs have been disclosed which combine a mobilerobot platform with a cleaning apparatus that is partially or fullyextending past the footprint of the mobile robot platform. Theseexamples include a robot with a flexible tail extending outside theshell of the cleaning robot, Proctor and Gamble, (“P&G”), robots with atrailing clearing module (S C Johnson and Minolta), as well as acleaning module that is movable relative to the mobile robot platform.(Minolta)

U.S. Pat. No. 6,779,217, assigned to P & G, discloses a mobile robotplatform which utilizes the standard circular design, but also includesa flexible “appendage” in the form of a triangular tail, where thetriangular tail holds a cleaning cloth. The advantage of this design isthat it can reach into corners with the extended tail, as well as cleanalong the edges of furniture and walls. However, the extended reach ofits cleaning abilities works only when the cleaning robot turns in placeto “sweep” along the radius of the turn. While the “appendage” approachprovides a beneficial supplementary function for catching extra dirt anddust, this approach does not overcome the limitation of the primarilycleaning mechanism being placed within the footprint of the mobile robotplatform. For example, if the cleaning robot drives along the side of awall, it will still not clean a majority of the gap between the primarycleaning mechanism and the wall, and will only do so in the limited areawhere the cleaning robot makes a turn.

S C Johnson, in U.S. application Ser. No. 10/218,843, disclosed aconfiguration which combines a circular mobile robot platform with atrailing external cleaning pad that could hold a cleaning cloth or othermaterial. This cleaning robot design allows the external cleaning pad tobe as wide as the cleaning robot, and provides that the edges of thecloth can extend past the width of the pad to reach along walls and intocorners. The drive system and sensors for the robotic cleaner would bein the front circular section as part of the mobile robot platform. Thelimitation of this design is the larger size and longer shape of thecombined form factor, which limits how well the robot would be able tonavigate in tighter spaces. This robotic cleaner configuration wouldhave the advantage of the standard circular design for turning alongwalls and, to some extent, maintain the benefits of being able to bumpand turn to get around forward obstacles. However, the extended lengthof the cleaning robot would provide challenges for turning in tighterspaces, as well as for getting in and out of cluttered environments,such as between chair and table legs which are clustered together. Theextra length of the trailing pad would prevent the cleaning robot fromnavigating into spaces a robot with just the circular section couldenter.

In U.S. Pat. No. 5,894,621, Minolta disclosed a similar robotic cleanerconfiguration of a cleaning pad trailing the mobile robot platform,where the pad would be larger than the robot body to allow greateraccess to walls and side cleaning. However, this configuration wouldstill have the same limitations of navigating in tight spaces given theoverall length and distance from the wheels to the cleaning pad.

In U.S. Pat. No. 5,720,077, Minolta disclosed another cleaning robotdesign where the cleaning mechanism is external to the mobile robotplatform. The cleaning robot expands its reach by making both (1) thecleaning mechanism's position adjustable to the mobile cleaning robotand (2) making the mobile robot platform drive wheels change the primaryaxis of direction, relative to the cleaning mechanism, in order to driveit in different orientations. This robotic cleaner design offers agreater degree of flexibility for cleaning in different spaces, butcomes at a price of significantly more cost and complexity.Specifically, this robotic cleaner design includes more moving parts andmore sensors to judge situational conditions and control the position ofthe cleaning mechanism, so this will likely result in a physicallylarger robot. While this may be appropriate for a commercial roboticcleaner for large office and commercial spaces, this disclosed cleaningrobot design would not fit the requirements of a consumer roboticcleaner needing to clean in tight spaces, such as around a kitchen tablethat is positioned close to one or more walls, which also includes anumber of chairs, as well as in places deep under low furniture.

The cleaning pattern and navigation strategy of consumer robots is alsoan area in need of improvement. The vast majority of current consumercleaning robots on the market utilize a random or semi-random navigationscheme for controlling the robot's driving behavior. This is primarilybecause in the past there has not been an effective and low-costnavigation solution that can track the robot's position and guide it tointelligently cover the desired area for cleaning the floor.

Instead, cleaning robots normally rely on a relatively simple set ofbehaviors and algorithms that combine driving, obstacle detection andavoidance, wall following and random variables in an attempt to “bounce”the robot around the floor space. The rationale is that over enoughtime, the robot will reach all locations in the cleanable area justthrough the process of randomly exploring the room.

This approach has several major limitations. First, the robot must cleanfor very long periods of time to reach full coverage of a room or otherdesignated area of a home. As noted in U.S. Pat. No. 6,076,025, the rateof new area covered drops significantly the longer the robot operates.Because the robot has little to no prior knowledge of where it hascleaned, it continues to clean over areas that it has already cleanedbefore as opposed to focusing on areas to it has not yet reached. Asmore area of the room or area of the home is covered, the random methodworks against the robot, as the robot spends proportionally more andmore time cleaning areas it has already cleaned. For a typical largeroom or area in a home, the robot runs out of battery power before it'sable to reach all locations in the target area.

In U.S. Pat. No. 6,076,025 (“the '025 patent”) assigned to Honda, Hondadiscloses an enhanced approach by having the robot periodically clean inan outward spiral pattern during the course of randomly navigatingthrough a room. This approach has the benefit of filling in more area indifferent locations and improving the efficiency curve relative to apure random approach, but the same core dynamic exists in terms ofmaking the robot becoming increasing inefficient as more of the room iscovered.

As another limitation, cleaning strategies that are described as randomor semi-random do not normally result in a random distribution ofcleaning coverage across a typical room or area of a home. In acompletely empty room where there are only walls and not interiorobstacles, each area of the floor will have an equal chance of beingcleaned within a certain amount of time. So on any given run, one partof the room is just as likely as another part of the room to getcleaned. As more runs are made or repeated, the odds increase that aspecific part of the room will be cleaned.

However, rooms and areas in homes are not empty, and instead have avariety of interior obstacles which the robot must navigate around.Additionally, these obstacles are not randomly dispersed. Rather, largeobstacles, namely furniture, are clustered together and form unevenbarriers of entry for a robot to navigate through. A common exampleincludes a dinning table and chairs, which create a “forest” offurniture legs concentrated in a certain area of a room. Another commonexample is a living room furniture set, such as a long couch, coffeetable, side chairs and side tables clustered in a pattern, such asU-shape or L-shape configuration.

In theory, the random approach gives infinite opportunities for therobot to find openings in the room between obstacles by hitting them inall points along their perimeter at virtually all angles. However, thisprocess takes time for enough permutations to take place and for a largepercent of those permutations, the robot may be frequently blockedand/or deflected away from areas occupied by these obstacles. The netresult is that the robot following a random approach is “corralled” awayfrom dense or blocked areas, and tends to stay into more open spaces.This often causes the robot to significantly over-clean some areas ofthe room or areas of the home while under cleaning other areas. In otherwords, a random and/or semi-random guided robot can systematically avoidand under-clean certain areas, over and over. This results in poorcleaning of those areas, inefficient use of energy, as well as excesswear on the robot and potentially of the floor covering in theover-cleaned areas.

These limitations of a random or semi-random approach, the general lowefficiency in reaching all areas of the floor, and the systematicpattern of repeatedly missing certain parts of the floor area, arecounter-productive to the primary cleaning function of the robot. Thisis especially true for robotic cleaners which use a consumable materialfor cleaning that has a limited period of use. As an example, forrobotic cleaners such as described in this invention which uses a wetcleaning pad, the dispersion of fluid on the floor would be concentratedin certain areas of the room, possibly to the point of pooling andleaving streaks and residue spots on the floor. At the same time, thepad dries up as it cleans, meaning areas that are not reached untillater will not be wet or cleaned at all.

To address these limitations, companies have proposed and in a fewinstances developed robots which use a systematic or semi-systematiccleaning strategy. These robots generally follow some pre-definedcleaning behavior or pattern, such as crossing the floor in parallelrows, to provide a more even and controlled method of cleaning the floorarea. For example, Samsung U.S. Pat. No. 7,480,958 discloses these typesof robots.

For open areas of a room, a parallel row pattern can be much faster atcovering a large amount of area in much less time than a randomapproach. These patterns can also have the benefit of using the drivingpattern to probe for open areas amidst obstacles that lie in the path ofthe rows. In the case of a robot cleaning in a pattern of parallel rows,the ends of the rows provide an opportunity to probe for open spacesbetween obstacles in a fast and systematic way. For example, if thedirection of the rows is roughly perpendicular to a boundary formed by acluster of furniture, then the robot has the opportunity to attempt topass into openings in the cluster on each returning pass. By controllingthe spacing on the rows and using heuristics for when to attempt tofollow around an obstacle, the robot can be much more methodical aboutfinding spaces in between obstacles that a random approach wouldinitially miss.

The challenge with systematic cleaning patterns is that the structure ofthe pattern may be too rigid to adapt enough for successfully coveringall areas in a complex environment. While a random cleaning strategyover time will allow the robot to find its way almost everywhere just bychance, although not efficiently or with equal success, a systematicstrategy alone can not guarantee full coverage. The problem is thepattern generally has one preferred direction and follows rules aboutwhich way to proceed when it has multiple directions to select from. Soin the example of the parallel rows, the robot may end up cleaning onside of a kitchen aisle, but miss the other side.

To make structured patterns work in unstructured environments, morecapabilities have to be added to the system to track the robot'sposition, keep a map of where it has cleaned and identify areas thathave not been reached. To date, very few systems have been developedthat would be suitable for a home cleaning robot. As one example, theSamsung® Hauzen® vacuum cleaning robot uses a camera to create a map ofwhere it cleans to provide some of these functions, but this productrequires complex image recognition software and more expensive sensorsand internal computing hardware built into the robot. To date, thisproduct is significantly more expensive than even the premium version ofthe leading models for robotic floor cleaners, and accounts for a verysmall share of the market. Evolution Robotics® has alternative vSLAM®localization system utilizing a camera and visual pattern recognition toconstruct a map of the environment, recognize where the robot is, andguide the robot, but this system too requires generally more processingand memory than is on the current generation of cleaning robots.Evolution's patents disclosing vSLAM localization system informationinclude U.S. Pat. Nos. 7,272,467; 7,177,737; 7,162,338; 7,145,478;7,135,992 and 7,015,831. For the vast majority of robots sold toconsumers, random or semi randomly cleaning remains to be the standard.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top perspective view of a robotic cleaner accordingto an embodiment of the invention;

FIG. 2 illustrates a side view of a robotic cleaner according to anembodiment of the invention;

FIG. 3 illustrates a top down view of the robotic cleaner according toan embodiment of the invention;

FIG. 4 illustrates a robotic cleaner with a shell removed according toan embodiment of the invention;

FIG. 5 illustrates a cleaning assembly separated from a robot drive bodyaccordingly to an embodiment of the invention;

FIG. 6 illustrates a drive assembly according to an embodiment of theinvention;

FIG. 7 is a bottom view of a robotic cleaner accordingly to anembodiment of the invention;

FIG. 8 illustrates a robotic cleaner with a movable cleaning padrelative to the robot drive body according to an embodiment of theinvention;

FIG. 9 illustrates a robotic cleaner with a shell removed according toan embodiment of the invention;

FIG. 10 illustrates a sensory system according to an embodiment of theinvention;

FIG. 11 illustrates a cleaning robot and a docking station according toan embodiment of the invention;

FIG. 12 illustrates a cleaning assembly of a cleaning robot with a topsurface of the cleaning assembly removed according to an embodiment ofthe invention;

FIG. 13 illustrates a block diagram of the robotic cleaner according toan embodiment of the invention;

FIG. 14 illustrates an embodiment of a robotic cleaner according to anembodiment of the invention;

FIG. 15 illustrates a three quarter view of a robotic cleaner accordingto an embodiment of the invention;

FIG. 16 illustrates examples of different cleaning modules for the mainrobot body;

FIG. 17 illustrates a side exterior view of a robotic cleaner accordingto an embodiment of the invention;

FIG. 18 illustrates a side cut-away view of the robotic cleaner withcovers removed according to an embodiment of the invention;

FIG. 19 illustrates a top view of a robotic cleaner according to anembodiment of the invention;

FIG. 20 illustrates a top view of a robotic cleaner with a cover (orshell) removed according to an embodiment of the invention;

FIG. 21 illustrates a back view of a robotic cleaner with a coverremoved according to an embodiment of the invention;

FIG. 22 illustrates a robotic cleaner with optional sensors according toan embodiment of the invention;

FIG. 23 illustrates a manual floor cleaning device with rotating brushesas a cleaning mechanism according to the prior art;

FIG. 24 illustrates a Swiffer sweeper in its packaging and also thecleaning pad assembly of the Swiffer Sweeper according to the prior art;

FIG. 25 illustrates a Swiffer® SweeperVac® according to the prior artwhich is a combination vacuum with dry pad cleaner;

FIG. 26 illustrates a Clorox Ready to Go Mop according to the prior art;

FIG. 27 illustrates a Swiffer® Wet Jet® according to the prior art;

FIG. 28 is a Swiffer® Scrubmagnet® device according to the prior art;

FIG. 29 illustrates a single pass parallel row cleaning patternaccording to an embodiment of the invention;

FIG. 30 illustrates a double-pass cross-row cleaning pattern accordingto an embodiment of the invention;

FIG. 31 illustrates a contour following cleaning pattern according to anembodiment of the invention;

FIG. 32 illustrates a combination of macro and micro cleaning patternsaccording to an embodiment of the invention;

FIG. 33 illustrates a deep cleaning pattern with a systematic pathaccording to an embodiment of the invention;

FIG. 34 illustrates a semi-random cleaning with a system patternaccording to an embodiment of the invention;

FIG. 35 illustrates a cleaning pattern with a refreshing stationaccording to an embodiment of the invention;

FIG. 36 illustrates a semi-random cleaning pattern in areas whereposition information is limited according to an embodiment of theinvention;

FIG. 37 illustrates embodiments of a robotic cleaner having a cleaningpad that can hold a cleaning cloth;

FIG. 38 illustrates embodiments of a robotic cleaner which have ahorizontal rotating brush as part of the cleaning mechanism;

FIG. 39 illustrates embodiments of a robotic cleaner including aloadable tray for holding multiple cleaning cloths, cleaning pads, orother material;

FIG. 40 illustrate embodiments of a robotic cleaner including a loadabletray for holding multiple cleaning cloths, cleaning pads, or othermaterial;

FIG. 41 illustrates embodiments of a robotic cleaner including a vacuumand collection bin in various configurations according to an embodimentof the invention;

FIG. 42 illustrates embodiments of a robotic cleaner which use one ormore vertically oriented scrubbing brushes mounted along the exterior ofthe robot according to an embodiment of the invention;

FIG. 43 illustrates embodiments of a robotic cleaner which includes ahorizontally oriented rotating brush with a spraying nozzle above thebrush that dispenses cleaning fluid in the area in front of the brushaccording to an embodiment of the invention;

FIG. 44 illustrates embodiments of a robotic cleaner which use one ormore vertically oriented scrubbing brushes mounted along the exterior ofthe robot according to an embodiment of the invention;

FIG. 45 illustrates an embodiment of a robotic cleaner where the robotis in a circular form and includes a vertically oriented circular brushthat extends to the outer of perimeter of the robot as a ring and spinsaround the robot's center axis according to an embodiment of theinvention;

FIG. 46 illustrates embodiments of a robotic cleaner which have ahorizontal rotating brush as part of the cleaning mechanism;

FIG. 47 illustrates various embodiments of a robotic cleaner which useone or more vertically oriented scrubbing brushes mounted along theexterior of the robot according to an embodiment of the invention; and

FIG. 48 illustrates additional embodiments of a robotic cleaner whichuse a vacuum as part of the cleaning mechanism according to anembodiment of the invention.

DESCRIBED DESCRIPTION OF THE INVENTION

In an embodiment of the invention, the cleaning robot solves a currentproblem of extending cleaning reach, while achieving reliable cleaningrobot mobility by using a unique configuration where the cleaningapparatus (e.g., the cleaning pad which holds the cleaning cloth) formsa major part of the mobile robot platform and overall body. In thisembodiment of the invention, the cleaning apparatus (1) is located atthe front of the cleaning robot to reach any part of the cleaning pathtravelled, (2) fully extends along the forward leading edge and sides ofthe cleaning robot to enable the cleaning cloth to reach to walls, alongfurniture, into corners and under low objects, (3) provides a largesurface at the bottom side of the cleaning pad for maximizing the floorarea covered by the cleaning cloth, (4) maintains maximum contactbetween the cleaning cloth and floor by utilizing the cleaning paditself as primary suspension point for the robot, and (5) minimizes thesize of the drive portion of the cleaning robot relative to the size ofthe cleaning pad, to enable the overall robot to be small and capable ofmaneuvering in tight spaces a larger robot could not reach.

In this embodiment, the cleaning robot is designed utilizing thecleaning mechanism (or apparatus) as the base module in the mobilerobotic platform, and then optimizing the remaining elements tocomplement the function of the cleaning apparatus.

This robotic cleaner configuration has additional advantages, whichinclude, but are not limited to: (6) providing a form factor where thefront of the robotic cleaner mimics the cleaning pad found onconventional manual cleaning mops that use an attachable cleaning cloth;(7) being compatible with standard size cleaning cloths sold for manualcleaning mops widely available on the market; (8) providing users animmediately familiar design that communicates its function; and (9)closely following a normal use pattern for attaching and removingcleaning cloths.

In an embodiment of the invention, a primary cleaning mechanism orassembly is a cleaning pad holding a dry or wet cleaning cloth. Inalternative embodiments of the invention, the function of the cleaningmechanism (or apparatus) is changed, but the core cleaning robotconfiguration remains the same. In one alternative embodiment of theinvention, a forward cleaning mechanism is included having a poweredrotating brush and dust collection bin, which is in a rectangular formlike the cleaning pad described in this invention. In this embodiment ofthe invention, the cleaning mechanism has one or more rotating brushesalong the front leading edge, and one or more dust bins located behindthe cleaning brushes in front of the wheels of the cleaning robot.

In another embodiment of the invention, the cleaning mechanisms orassemblies are detachable and swappable, so that a cloth cleaning padholder can be removed from the robot and replaced with a compatiblecleaning module that features, for example, the powered rotating brushand collection bin. In this embodiment, the compatible cleaning modulemay have both a physical interface for locking and unlocking with therest of the cleaning robot, as well as an electrical interface forproviding power from the cleaning robot to the compatible cleaningmodule, as well as provide any data communication between sensorslocated on the cleaning module and the robot's main computing unit.

In another embodiment of the invention, the cleaning assembly maysupport an automatic cloth changing function to allow the robot tooperate for longer periods of time before requiring action from theuser. In one embodiment of this function, the user may load multiplecleaning cloths onto the robot cleaning assembly, and the robot canmechanically remove a cleaning cloth to change to a fresh one. Thetrigger for removing a cleaning cloth may include but is not limited to:duration of cleaning time for a given cloth, amount of area covered witha given cloth, and/or sensing of the amount of dirt built up on a cloth,such as through utilizing a reflective light sensor position near thecloth. The user may have options for setting when and under whatconditions the cloth is removed. The main body of cleaning robot mayinclude cleaning cloth software, located in memory in a microcontrolleror in a separate memory, that identifies when a cleaning cloth needs tobe removed. Alternatively, the cleaning assembly may include a sensorwhich is connected to the microcontroller in the main robot body thatidentifies an amount of dust built up on a cloth and transfers suchinformation to the microcontroller.

The mechanism for removing a cleaning cloth by the robot may include butis not limited to: having a motorized hook on the robot, such as a hookor set of hooks on a tread that rotates over an area of the cloth tograb the outer cloth and pull it back into a storage area on the robot,leaving a fresh cloth exposed to continue cleaning. In anotherembodiment of the invention, the cleaning robot may drive to an externalpad changing device, where the robot drives to physically dock with thepad changing device, and the pad changing device includes a mechanicalhook or set of hooks that make contact with outer cloth to remove it,either through powered rotation of the hooks to pull the cloth off,through a process of have the robot drive back away from the device asthe hook or hooks on the pad changing device statically pull thecleaning cloth of the cleaning pad, or a combination of the two systems.

In another embodiment of the invention, the cleaning mechanism mayinclude a cleaning cloth which is stored on a roll, where the cleaningcloth is fed from out of the roll, transitions across the bottom surfaceof the cleaning pad, and into a collection mechanism. In an embodimentof the invention, the collection mechanism may be a rotating dowel,which pulls on the cleaning cloth as it turns, and advances the clothroll so that the section of the cloth that has been exposed to floorsurface beneath the pad may advances to allow a new clean section of thecloth to be used. This mechanism allows the robot to roll a section ofcleaning cloth as it becomes dirty off the pad and replace it with aclean section. In embodiments of this invention, the trigger foradvancing the cloth may include but is not limited to duration ofcleaning time for a given section or area of the cloth, amount of areacovered with a given section or area of the cloth, and/or sensing of theamount of dirt built up on a section or area of the cloth, such asthrough utilizing a reflective light sensor position near the section ofthe cloth exposed to the floor. The user may have options for settingwhen and under what conditions the cloth is advanced. In an embodimentof the invention, the cleaning cloth roll may be attached by the user asa roll that loads into the cleaning mechanism, where the user feeds theroll onto a collecting spool included in the cleaning mechanism. In anembodiment of the invention, the cleaning cloth roll may be packagedwithin a cartridge with contains both the original roll and a collectionspool for advancing the cloth material and rolling up the used material,along with mechanical and/electrical connections which allow the robotto control and advance the roll.

Embodiments of the invention as well as additional embodiments usingalternative cleaning mechanisms or modules are disclosed below.

FIG. 1 illustrates a top perspective view of a robotic cleaner accordingto an embodiment of the invention. As illustrated in FIG. 1, the roboticcleaner 10 includes a cleaning assembly 11 and a robot drive body 12.The cleaning assembly 11 is located in a front part of the roboticcleaner and provides a rectangular form for attaching the cleaning cloth(not shown). The cleaning assembly 11 connects to the robot drive body12 to form the overall mobile robot platform 10. The cleaning assembly11 includes a top 16 and a bottom pad 17 for holding the cleaningassembly 11 to the floor. The top 16 may be a hard, flat plastic top ormay be made of other material. The bottom pad 17 may be a soft rubberpad. The bottom pad 17 extends around the bottom and lower edge of thetop 16 to provide a surface for the cleaning cloth to wrap around thesides. The bottom pad 17 also provides a flexible edge for when therobotic cleaner makes contact with walls, furniture and other obstacles.This configuration of the cleaning assembly 11 is similar to thestandard placement of cleaning cloths on manual mops, and provides allthe of same cleaning advantages provided by exposing a broad bottomsurface area as well as side edges as part of the cleaning cloth. Forexample, it allows the cleaning assembly 11 to reach into corners, alongwalls, under and around furniture and other objects.

FIG. 5 illustrates a cleaning assembly separated from a robot drive bodyaccordingly to an embodiment of the invention. FIG. 5 shows the twoelements in isolation, with the cleaning assembly 51 separated from therobot drive body 52 to show the boundaries of the two elements and theirrelative size with respect to one another. In the embodiment of theinvention illustrated in FIG. 5, the cleaning assembly 51 may bedetachable from the robot drive body 52.

FIG. 3 illustrates a top down view of the robotic cleaner according toan embodiment of the invention. The cleaning cloth is attached to thecleaning assembly 32 through four plastic cloth holders 33 a, 33 b, 33 cand 33 d mounted at the corners of the top 32 of the cleaning assembly.Referring back to FIG. 1, the shape of the cleaning assembly 11 is veryclose in the design to standard manual cleaning mops that use disposablecleaning cloths, and is compatible with the standard sized cleaningcloths used by those mops.

In an embodiment of the invention, the cleaning assembly 11 is notremovable (or detachable) from the main robot body 12, but the cleaningassembly 11 may slide out forward a few centimeters from the robot drivebody 12, like a drawer. In this embodiment of the invention, thecleaning assembly 11 may be pulled away from the robot drive body 12,and a user may drape one end of the cleaning cloth around the rear ofthe cleaning assembly 11 and lock it into the rear cloth holders (e.g.,19 c and 19 d of FIG. 1), then wrap it around the front and lock it into the front cloth holders (e.g., 19 a and 19 b of FIG. 1), just likethe user would on a normal manual mop for cleaning clothes. Once doneattaching the cleaning cloth, the user pushes the cleaning assembly 11back into a closed position relative to the robot drive body 12.

FIG. 8 illustrates a robotic cleaner with a movable cleaning padrelative to the robot drive body according to an embodiment of theinvention. As is illustrated in FIG. 8, the cleaning assembly 82 can bemoved away from the drive body 84 as is illustrated by the arrow 85.This movement creates a space 81 between a bottom part of the robotdrive body 84 and the cleaning assembly 82.

In another embodiment of the invention, the cleaning assembly may open agap up between the cleaning assembly and a robot shell in a differenttype of configuration than sliding out, but with the same effect ofcreating a gap for attaching and removing the cleaning cloth. Thisembodiment of the invention may include having the cleaning assemblypull out at an angle relative to the robot shell, such as in a directionthat combines downward and forward movement relative to the shell ratherthan strictly forward movement relative to the shell. In anotherembodiment of the robotic cleaner, the cleaning assembly may swing openfrom the rear of the cleaning assembly, with the cleaning assemblypivoting at a forward point near the front of the shell, and the rear ofthe cleaning assembly drops below the level of the wheels to open up agap for attaching and removing the cleaning cloth along the rear of thecleaning assembly.

In an embodiment of the invention, the cleaning assembly 11 is comprisedon a hard, flat plastic top 16 and a soft rubber bottom pad 17 forholding the cleaning cloth to the floor. The soft rubber bottom pad 17extends around the bottom and lower edge of the plastic top 16 toprovide a surface for the cleaning cloth to wrap around the sides. Thesoft rubber bottom pad 17 also provides a flexible edge for when therobotic cleaner makes contact with walls, furniture and other obstacles.This configuration of the cleaning assembly 11 is similar to thestandard placement of cleaning cloths on manual mops, and provides allthe of same cleaning advantages provided by exposing a broad bottomsurface area as well as side edges as part of the cleaning cloth. Forexample, it allows the cleaning assembly 11 to reach into corners, alongwalls, under and around furniture and other objects.

FIG. 3 illustrates a top down view of the robotic cleaner according toan embodiment of the invention. In the embodiment of the inventionillustrated in FIG. 3, the cleaning assembly 32 comprises nearly half ofthe overall footprint of the robotic cleaner, which provides for a largesurface area for cleaning within a small bodied robotic cleaner. FIG. 7is a bottom view of a robotic cleaner accordingly to an embodiment ofthe invention. FIG. 7 further illustrates the footprint of the cleaningassembly 71 in relation to the overall robotic cleaner. As illustratedin FIG. 3, the robot drive body 31 may be covered by a shell 38. In theembodiment of the invention illustrated in FIG. 3, the robot drive body31 extends over a middle top section of the cleaning assembly 32 in thefront of the robot. In an embodiment of the invention, a rear portion ofthe robot drive body 31 houses at least one motor, batteries, and leftand right drive wheels. Reference numbers 35 and 35 point to the side ofthe shell 38 that covers the left and right drive wheels. In anembodiment of the invention, the left and right wheels are set insidethe shell 38 a few millimeters. The shell 38 extends over the left andright drive wheels. The left and right drive wheels are independentlycontrolled to provide a differential drive system. The placement of thewheels so closely behind the cleaning assembly 32 provides a tightturning radius for the robotic cleaner and also provides the roboticcleaner 30 with a small length for getting in and out of tight spaces.The wheels are nested into the robot drive body 31 so that the width ofthe drive body is narrower than the width of the cleaning assembly 32,as is illustrated in FIG. 3. This configuration allows the cleaningassembly 32 to extend to reach along walls and also provides a widersweep of coverage when cleaning.

As illustrated in FIG. 3, the combination of a large exterior cleaningassembly 32 with a minimally sized robot drive body 31 provides a morecompact yet effective design for cleaning household floors. By contrast,in the traditional cleaning robot designs, the cleaning assembly wouldneed to be either shrunk down to fit within a body of a circular robot,or the circular robot body would have to be significantly larger (andthus be less able to fit into tight spaces) to provide enough internalspace for holding a full size cleaning assembly.

Returning to FIG. 1, the robot drive body 12 makes contact with thefloor with two wheels, a left wheel 15 and a right wheel (not shown),located behind the cleaning assembly 11 at the outer left and rightedges of the drive body 12, respectively. The cleaning assembly 11provides a 3rd area of contact on the floor. In the embodiment of theinvention illustrated in FIG. 1, the bottom pad (along with a cleaningcloth) provides a 3^(rd) area of contact on the floor. The cleaningassembly 11 runs along the surface of the floor with the cleaning clothproviding both the cleaning function as well as skid surface to allowthe cleaning robot 10 to travel across the floor surface, as if thecleaning assembly 11 was a ski. This 3 area system ensures that eachpoint, the two wheels and the cleaning assembly 11 with the cleaningcloth, maintains contact with the floor during normal operation.

FIG. 4 illustrates a robotic cleaner with a shell removed according toan embodiment of the invention. FIG. 4 shows the 3 areas of contact withthe shell of the robotic cleaner 40 removed, with the right wheel 43 aand the left wheel 43 b and the cleaning assembly 44. The 3 area contactsystem eliminates the need for any other support, such as having acaster wheel in addition to the two drive wheels (e.g., 43 a and 43 b).The use of a caster wheel for additional support is typical on most allrobot vacuum cleaners to stabilize the mobile robotic platform.

FIG. 2 illustrates a side view of an embodiment of a robotic cleaneraccording to an embodiment of the invention. In the embodiment of theinvention illustrated in FIG. 2, the robotic cleaner 20 includes acleaning assembly 26, a robot drive body 23, and wheels (one of which isshown, wheel 25). The cleaning assembly 26 is located under the front ofthe robot body 23 and the wheel 25 located under the rear of the robotbody 23. The bottom surface 21 (e.g., the bottom pad) of the cleaningassembly 26 is slightly curved (e.g., from front to back of the cleaningassembly) in relation to the floor, following the standard design ofmanual floor mops that use cleaning cloths. This curve helps thecleaning cloth pick up dust and dirt that would otherwise collect in thefront of a flat cleaning pad. Through the robotic cleaner's forwardmotion, the curve pushes dust and dirt under the cleaning pad and usesmore of full surface area of the cleaning cloth along the bottom pad ofthe cleaning assembly 26 to trap the dust and dirt onto the cleaningcloth. The cleaning assembly 26 may be slightly curved in the front, theback or both the front and the back. A curve in the back allows therobot to trap more dirt when the robotic cleaner is driving in reverse.In the embodiment of the invention illustrated in FIG. 2, the curvaturein a bottom surface 21 of the cleaning assembly 26 also allows thecleaning assembly to maintain even contact with the floor when thecleaning assembly 26 pitches slightly up or down on uneven floors.

The robot drive body is covered by a shell 29 (in FIG. 2) and 38 (inFIG. 3) which covers the wheels and all internal electrical andmechanical parts of the robot drive body 31 (in FIG. 3) and 23 (in FIG.2). The shell 29 provides openings for sensors, such as a navigationsensor 14 (in FIG. 1), 22 (in FIG. 2) and 37 (in FIG. 3). The shell 29also provides openings for buttons and lights 39 (in FIG. 3) and 13 (inFIG. 1) which provide the user interface for the robotic cleaner 20. Inthis embodiment of the invention, the shell 29 may also include a handle24 for carrying the robotic cleaner, which in FIG. 2 is located at therear of the robotic cleaner 20 (e.g., behind the wheels 25 and on a backsurface of the shell 29).

The shell 29 may also provide a critical function relative the cleaningassembly 26, in that in closes off any open gaps or catch points betweencleaning assembly 26 and the rest of robotic cleaner 20 when thecleaning assembly 26 is in the closed position. If open gaps wereexposed, the robotic cleaner 20 may catch on wires or other objects andget tangled. As illustrated in FIG. 2, a bottom edge 27 of the shell infront of the wheels 25 provides a smooth lock (engagement or fit) withthe cleaning assembly 26 when the cleaning assembly 26 is in the closedposition. In the embodiment of the invention illustrated in FIG. 2, aback portion of the cleaning assembly 26 forms a smooth fit (orengagement) with the bottom edge of the shell. In this embodiment of theinvention, an enclosed space 28 is provided between the rear of the padand the shell to allow the rear edge of the cleaning cloth to rest underthe shell.

If the cleaning assembly is in the closed position, the cleaningassembly and shell are rigid relative to one another and form a unitthat moves together. If the cleaning assembly is lifted, the shell moveswith the cleaning assembly. This robotic cleaner configuration alsoapplies weight and stability to the cleaning pad. For example, if thecleaning robot drives into an obstacle and a force pushes on thecleaning assembly in a direction where it would push the front of thecleaning assembly down and the rear of the cleaning assembly up, theweight of the shell and the resistance of the spring holding the shellover a rear drive assembly of the robotic cleaner would provide leveragefor counter-acting that force.

In another embodiment of the robotic cleaner, the cleaning assembly maybe designed to freely pivot in one or more directions relative to theshell. The cleaning assembly may freely pivot relative to the shellbecause there is no rigid connection between the cleaning assembly andthe shell. Rather, the two components (i.e., shell and cleaningassembly) would be joined by a pivot joint that provides the desiredmovement in one or more directions. In this configuration of the roboticcleaner, a gap around the top and the rear of the cleaning assembly withrelation to the shell would be present, to allow space for the cleaningassembly to move, such as to tilt up and down (or move side-to-side). Inthis embodiment of the robotic cleaner, a flexible gasket or skirt on asurface of the shell around or near the cleaning assembly may close offthe gap, while still allowing the cleaning assembly to move, and thismay present the gap from becoming a catch point for dust or otherdebris. FIG. 14, described later, illustrates a robotic cleaner with aflexible skirt around a bottom of a forward section of the shell tocover the gap between the shell and the cleaning assembly. In anembodiment of the invention where the shell and cleaning pad lock or areclosed together, the gasket or skirt may be eliminated.

If the cleaning assembly and shell lock or close together, a roboticcleaner drive system including the two wheels is designed to moveindependently relative to the cleaning assembly and the shell. Thisconfiguration allows the wheels to maintain contact with the floorregardless of the cleaning assembly position. To achieve this freedom ofmovement and maintain all three areas on contact on the floor, the drivesystem may be connected to the shell and cleaning pad through a pivotjoint assembly. FIG. 9 illustrates a robotic cleaner with a shellremoved according to an embodiment of the invention.

FIG. 9 is a top perspective view of the robotic cleaner with the top ofthe shell removed. The pivot joint 91 connects on one end to a mountingplate 92 near the front of the robotic cleaner. This mounting plate 92is a fixed part of the robot drive body and connects to the base of theshell. It may also provide support areas for internal electronics housedunder the forward section of the shell, such as a PCB 41 (see FIG. 4).The PCB 41 may be located in a position above the mounting plate 92. ThePCB 41 may be mounted to the mounting plate 92 via posts. The mountingplate 92 connects with top of the cleaning assembly 94, and may providea sliding mechanism that allows the user to move the cleaning assembly94 in and out from the robot drive body. In this embodiment of theinvention, the sliding mechanism may include a stop to limit how far thecleaning assembly may be pulled out relative to the shell. In anotherembodiment of the robotic cleaner, the sliding mechanism may be designedin such a way that the entire cleaning assembly may be pulled off of themounting plate. In another embodiment of the robotic cleaner, thecleaning assembly may connect with the shell and not directly interfacewith the mounting plate, where the connection between the shell and thecleaning assembly provides for the desired means of moving the cleaningassembly relative to the shell.

Also connected to the pivot joint 91 is a center bracket 93 whichconnects to the drive box 95. The drive box 95 is connected to the leftand right wheels 96 and 97, to form the inner drive assembly. Theinternal motor assemblies supporting the wheels 96 and 97 (e.g. motor,gearbox and drive shaft) in an embodiment of the invention, are mountedrigidly to the drive box 95, allowing for strong traction and stabilitywhen travelling over the floor.

This configuration, in combination with the pivot joint 91, allows thedrive assembly to lift up and down relative to the cleaning assembly (aswould be seen from a side view), as well as roll relative to thecleaning assembly 94 (as would be seen from a rear view.) Thismechanical configuration provides a simple but highly effective gravitybased suspension system, where the any one of the 3 areas of contact(i.e., wheels 96 and 97 or cleaning assembly 94) on the floor can liftor fall relatively freely without impacting the other areas of contact.

In this embodiment of the invention, the shell is locked with the motionof the cleaning assembly, and room is provided within the shell to allowfor movement of the drive assembly. A spring 98 provides support for theshell in the rear of the robotic cleaner over the drive box 95. In anembodiment of the invention, the spring 98 is set along center axis ofthe robot so that the shell can “float” over the drive assembly withoutputting much resistance on the ability of the wheels 96 and 97 to moveup and down within the shell. The broad width of the cleaning assembly94 over the floor provides additional stability to the shell, so whilethe drive box 95 and wheels 96 and 97 may twist within the shell, theshell itself stays very level because it is stabilized by the cleaningassembly 94.

In this embodiment of the invention, the shell can compress over thedrive box 95 when pressed down from a force external to the roboticcleaner. This has two advantages. First, the shell may lower down if therobotic cleaner travels under low clearance furniture and this may avoidthe robotic cleaner getting wedged in place. In addition, a limit orcontact switch 99 may provide detection if the shell compresses below acertain safety point, triggering the robotic cleaner to reverse itscourse before it gets wedged.

The ability of the shell to compress on the rear spring 98 also providesroom for the shell to drop if the shell is stepped on or has somethingdropped on top of it. In an embodiment of the invention, a rubber pad isplaced along the bottom of the shell at the rear handle 24 (see FIG. 2)so that if the shell is pushed to the ground, the rubber pad wouldprovide a stopping point with a non-slip grip to the floor. The spacingis such that the shell will make contact with the floor prior to thepoint where the shell would make contact with the drive box 95 (see FIG.9). As an added precaution in an embodiment of the invention, theclearances between the shell and the drive box would result in the shellmaking contact with the rubber tires 25 (see FIG. 2) and come to rest onthe tires 25 before compressing directly on the drive box 95 and puttingpressure on it or any other internal structures.

A post at the back of the drive box can fit into a slotted guide railalong the rear inner shell (in front of a handle recess) for keeping thedrive box aligned in place along the cleaning robot axis. This post andrail may also provide a drop limit for setting how far the drive box andwheels can fall away from the shell. In an embodiment of the invention,the post can be set so that it compresses that spring with some tensionwhen the shell is in its level position, providing for a firmer hold onthe shell, but still provide some degree of freedom in the driveassembly. In another embodiment of the invention, the post and rail canbe set with adequate clearance, so that in the level position, the shellis lightly resting on the spring, and the drive box has free room todrop without interference.

In another embodiment of the invention, the placement of the post and/orbottom limit may be adjustable by the user through a mechanicalinterface, such as a sliding switch with different preset positions. Byusing a sliding switch with different preset positions, a user mayadjust the tension and freedom of movement of the robotic cleaner tooptimize the suspension for their environment. In addition, in anembodiment of the invention, one or more limit switches may be used todetect if the wheels have dropped as an added safety measure to turn themotors off if a wheel loses contact with the floor surface or detectthat the user has lifted the robot up.

FIG. 6 illustrates a drive assembly according to an embodiment of theinvention. FIG. 6 illustrates the primary components of the driveassembly, including the center bracket 67 which connects to the pivotjoint 68 and travels relative to the mounting plate 62. FIG. 6 alsoillustrates the drive box 69 which holds the motors 65 a, 65 b,batteries 63 and the wheels 61 a and 61 b. In this embodiment of theinvention, the batteries 63 are centered over the drive box 69 toprovide weight for the wheels to maximize traction with the floor. Thedrive box also includes the gear box 64 a 64 b attached to the motor 65a 65 b for reducing the RPM to the target speed of the wheels 61 a and61 b and for generating enough torque to push the cleaning pad (notshown), and drive box 69 also includes the wheel tachometers 66 a 66 bto measure the effective rotation of the wheels 61 a and 61 b.

In addition to mechanical design of the robotic cleaner, the sensorysystem is also important to allow the cleaning pad to be fully exposedand not fit within the traditional designs of robotic floor cleaners.

In an embodiment of the invention, one specific design consideration isthat the cleaning cloth of the cleaning assembly fully cover the leadingedge of the cleaning assembly. The cleaning assembly and cleaning clothare designed to have the cleaning cloth make full contact with walls andobjects in its path, and thus there is no room for mechanical devicessuch as bumpers or feelers obstructing the cleaning cloth. Further, itis difficult for there to be proximity sensors placed in the cleaningassembly in any way where the cloth may cover them. This also appliesfor ease of use, so that the users do not have to work around anymechanisms when placing the cloth on the cleaning assembly.

By comparison, traditional robotic cleaners use simple contact sensingdevices to detect obstacles, such as a bump sensor, mounted on theleading edge of the main robot body. Additionally, the same robots mayalso use one or more IR distance sensor or other type of proximitysensor placed along the leading edge of the robot to detect obstacles inthe robots path and help avoid them. This placement of sensors along theleading edge of the robot is a very common design, and is in part one ofthe factors that drives these standard robots to place the cleaningmechanism within the robot body, so that its design and operation doesnot interfere with the sensors.

In the cleaning mechanism-centered approach described herein,alternative sensors or sensing techniques may be utilized to detectobstacles or drops in surface levels. For bump detection (or detectionof obstacles), the robot's main controller (MCU) may detect increases inthe motor current, which generally means that the robotic cleaner hashit an obstacle and the wheels are generating additional load on themotors while attempting to still move the robotic cleaner on its desiredcourse. In an embodiment of the invention, a current sensor may transmitthis information to the MCU. For wet cleaning application, where thewheels may slip too easily due to loss of traction, in order for enoughcurrent load to be detected, an accelerometer may be added to supplementthe robotic cleaning system to detect changes in movement withoutrelying on the wheels. The accelerometer may transmit information to theMCU. In both embodiments of the invention, the sensing function isdelivered by internal systems within the robot, thus minimizing theexternal constraints on the robot's exterior design.

In another embodiment of the robotic cleaner, a gyroscope may be used toenhance the functionality of the robotic cleaner while maintaining itsnon-traditional design. Most traditional robotic cleaners include sometype of edge cleaning behavior, often referred to as wall following. Inwall following, the traditional configuration was to use side mounted IRproximity sensors to allow the robot to follow parallel with the wall,but just slightly away from the wall, to minimize bumping with the wall.In these traditional robotic cleaners, the bumping could trigger therobot's mechanical bump sensor as well as mark up the wall and furnitureover extended periods of contact.

In the robotic cleaner described herein, where the cleaning pad is fullyexposed and set to be wider than the shell of the robot, the functionfor edge cleaning requires that the cleaning robot purposely engages andrubs along the wall with the cleaning cloth wrapped around the sides ofthe cleaning pad, rather than avoiding the wall at a distance. In oneembodiment of the invention, a gyroscope may be used to help performthis function, whereby when the cleaning robot makes contact with thewall, turns in one direction, and then drives with slightly more speedon the wheel opposite the wall, causing the side of the cleaning padnear the wall to plow in toward the wall and drive along it whilecleaning. In this embodiment of the invention and under theseconditions, the gyroscope may be used to help determine that thecleaning robot is maintaining a straight heading along the wall eventhrough the wheels are purposely slipping to keep pressure against thewall.

In another embodiment of the robotic cleaner, the same approach may beused to clean along furniture and around obstacles, where the edge maynot be a straight line. When the edge is not a straight line, the sameplowing technique is used to hug along the furniture or obstacle, andthe gyroscope provides information about the robot's amount of turn tothe microcontroller (MCU) that allows the MCU to compare the estimatedturn from the wheels tachometers and, and if there is a differencewithin a certain threshold, determine the presence of surface providinga resisting force.

In another embodiment of edge cleaning, the robotic cleaner may leveragethe flat shape of the leading edge of the cleaning pad to alignperpendicularly with walls and other straight surfaces such as arearugs, and the gyroscope is used to then turn the robot 90 degrees toclean in a direction parallel with the wall or the area rug.

In another embodiment, the gyroscope can support the robotic cleanerfunctionality by also supplementing the bump detection system,(especially on a wet surface). The gyroscope may indicate that therobotic cleaner may be twisting when one side of the pad hits anobstacle. The information from the gyroscope may be provided to themicrocontroller (MCU) which would instruct the drive assembly to operateand have the cleaning robot to avoid the obstacle. This would allow thewheels to continue to spin and drive the cleaning robot to skid aroundthe obstacle if desired. In a similar application, the gyroscope mayindicate that the robot is not turning when it gets blocked by anobstacle on a turn, and the wheels are continuing to spin.

In another embodiment, the microcontroller (MCU) may make use of therobot's geometry in combination with the gyroscope to determine thegeneral location of an obstacle. As one example, by having a straightand wide leading edge to the front of the robot (as the cleaning pad andcleaning assembly provide), and having the wheels nested in narrowerthan the width of the cleaning pad, the robot will experience differentrotational forces when it hits an obstacle based on the location of theobstacle. For example, if the cleaning robot drives into a chair legwhere the right side of the cleaning pad makes contact with the chairleg, the placement of the wheels will create a tendency for the oppositeside of the robot to rotate forward and the right side is held back bythe chair leg. If the cleaning robot hits the chair leg on the oppositeside of the pad, the rotational force with be in the opposite direction.And if the robot hits the chair leg in the middle of the cleaning pad,the rotation force will be centered and canceled out. By measuring thedegree of turn when contacting an obstacle, the gyroscope may allow themicrocontroller (MCU) to estimate the position of the obstacle relativeto the robot, and use that as input to plan a path around the obstacleor perform other maneuvers. This approach provides the benefit of whatwould normally require a segmented bumper or multiple proximity sensorsin the front of the robot to determine obstacle location, without theneed to use such sensors and keep the leading edge of the cleaningassembly free of obstructions. In embodiments of the invention, asimilar method may be used to detect obstacles along the sides or rearof the cleaning robot based on the resisting rotational force created bythe contact with the obstacle. In embodiments of the invention, backcurrent from the motors, wheel tachometer input, accelerometer inputand/or other sensors feedback regarding the cleaning robot's motion maybe incorporated to assist in detecting contact with an obstacle and/orto help in measuring the direction of the resistance force from theobstacle.

FIG. 10 illustrates a sensory system according to an embodiment of theinvention. FIG. 10 shows a sectional view of the cleaning assembly. FIG.10 provides another example of adjusting the sensory function to fitwithin the cleaning mechanism. In traditional robotic cleaners, IRsensors are used to detect drop-offs in the floor surface to prevent tothe robot from driving off ledges and down stairs. To function, thedrop-off sensors need to be placed far enough in front of the wheels toallow the robotic cleaner to stop in time. They also need to be pointingrelatively straight down with relation to the floor and are thus hiddensome place under the robotic platform. The cleaning assembly provides achallenge for using traditional IR sensors, in that there is no place tolocate the traditional IR sensors on the pad, since the cleaningassembly is covered by a cleaning cloth during normal operation.

In an embodiment of the invention illustrated in FIG. 10, a custom dropsensor system is used, which is built into the cleaning assembly itself.The system comprises of a mechanical lever 106 that is mounted on oneend on a single pivot 103, and where the other end has a weighted object101 that extends through a hole in the cleaning assembly. In anembodiment of the invention, the hole may be in the bottom pad of thecleaning assembly and keeps the lever 106 in a level position while theobject is being supported by the floor surface beneath the cleaningassembly and the cleaning cloth. If the cleaning assembly begins totravel over a ledge, the weighted object 102 will drop to a lowerposition (as illustrated on the right hand side of FIG. 10) just as theweighted object cross over the edge, and the lever will tilt down withit to trigger a contact switch 105 or 104 or other limit detectingsensor which is wired to the robot's MCU to trigger the avoid behavior(or to stop the robotic cleaner from moving in this direction).

Because the weighted object 101 is mounted toward the middle of thecleaning assembly relative to the points where the cleaning cloth wrapsaround the forward and rear edges of the cleaning pad, the natural play(or travel) in the cloth material allows the weighted object 101 to dropeven when the user wraps the pad tightly on top. In an embodiment of theinvention, a small amount of flexible material may be permanentlyaffixed over the drop sensor 101 and 102 to provide a sealed barrier forpreventing fluid from a wet cleaning pad or dust from seeping into thecleaning assembly through the opening around the drop sensor 101 and102.

FIG. 11 illustrates a cleaning robot and a docking station according toan embodiment of the invention. The docking station 110 may also bereferred to as a docking bay. In an embodiment of the invention, therobotic cleaner 116 may drive up to a docking station 110. The dockingstation 110 may include a ramp 112 and in one embodiment of theinvention, the ramp 112 may be a foldable ramp. The docking station mayinclude a pad removing strip 113. In this embodiment of the invention,the pad removing strip 113 may take used pads off of the cleaningassembly. The docking station 110 may include a used pad storage well115. The docking station 110 may include charging connections 114. Thecharging connections 114 may dock with a rear section of the roboticcleaner. The docking station 110 may include a NorthStar room projector111 to provide a localization signal. In an embodiment of the invention,the docking station may include a secondary navigation beacon, which maybe located on a front part of a top section of the docking station 110to provide a directional signal for helping the robot locate, align withand/or drive into the docking station. In an embodiment of theinvention, the docking station 110 may include a new pad storage well.

FIG. 13 illustrates a block diagram of the robotic cleaner according toan embodiment of the invention. The robotic cleaner may include acentral microcontroller unit (MCU) 130, a power management module 131, awedge sensor 132, a battery 132 b, an H-bridge 133, a current sensor134, an encoder 134 e, user interface buttons 135, and LEDs 135 a. Therobotic cleaner may also include drop sensors 136. The MCU 130 is acentral microcontroller unit responsible for running all navigationsoftware and cleaning software, servicing sensors (e.g., receivinginformation and controlling sensors), receiving information andcontrolling user interface buttons 135, and interfacing with the powermanagement module 131. In an embodiment of the invention, the navigationsoftware and the cleaning coverage software is stored in memory on themicrocontroller. In an embodiment of the invention, the navigationsoftware and the cleaning coverage software is stored in a memoryseparate from the microcontroller. The memory, which includes thenavigation software and the cleaning coverage software may be updateableor modifiable. The power management module 131 includes electronics andcircuitry responsible for controlling battery charging, limitingcharge/discharge currents to ensure safety, and conditioning the batteryvoltage. The wedge sensor 132 is utilized to detect situations where therobotic cleaner is about to get jammed under obstacles, e.g., lowclearance furniture.

The drop sensors 136 are designed to detect sudden drops in the front ofthe robotic cleaner such as stairways and other types of ledges. In anembodiment of the invention, the drop sensors 136 may also detect if thecleaning assembly is lifted up from the floor, such as if the robotdrives onto the edge of a rug or other low object, as a means to avoiddriving onto those areas. A motor control module 133 is an electronicsassembly or circuitry for controlling torque, speed and direction ofrotation of the DC motor. The motor control module may be an H-Bridgewhich is utilized for controlling a brushed DC motor. The current sensor134 may provide current feedback to a control algorithm for the DCmotor. In an embodiment of the invention, the control software may belocated in memory in the microcontroller 130. The encoder 134 e providesspeed and direction of rotation feedback for the control algorithm ofthe DC motor. The user interface buttons 135 are located on the roboticcleaner. The user interface buttons 135 include buttons for power on/offand cleaning mode selection. The LEDs 135 a are light emitting diodesfor providing visual feedback to a user. The LEDs may provide feedbackon battery status, charging status and cleaning mode types.

The robotic cleaner may include a buzzer 135 b. The buzzer is a speakerfor providing audio feedback to the user.

In an embodiment of the invention, a robotic cleaner may include agyroscope 137. The gyroscope 137 may sense changes in the roboticcleaner's orientation. In an embodiment of the invention, the roboticcleaner may include a sweep generator 137 b. The sweep generator 137 bis a circuit that provides a calibration circuit for ananalog-to-digital converter. In an embodiment of the invention, therobotic cleaner may include a 2D accelerometer 138. The 2D accelerometer138 is a sensor for measuring sudden changes in robot velocity. The 2Daccelerometer may measure changes in velocity in two directions. The 2Daccelerometer 138 assists in detecting bumping into obstacles anddetecting robot kidnapping, e.g., when a robotic cleaner is picked upand moved by the user. The 2D accelerometer provides any detected changein velocity information to the MCU 131. For example, when a roboticcleaner bumps into an obstacle, the velocity of the robotic cleanerchanges rapidly and the 2D accelerometer detects these changes.Similarly, if a user picks up a robotic cleaner, the accelerometer maydetect a slowly changing velocity (or acceleration) caused by gravityand the user motion.

In an embodiment of the invention, the robotic cleaner may include aNorthStar® sensor 139. The NorthStar® sensor provides absolute positionof the robotic cleaner relative to one or more infrared spots projectedonto the ceiling or other surfaces above the robot by one or moreexternal projecting devices and supplies this information to the MCU 130for utilization by navigation software. In an embodiment of theinvention, NorthStar® sensor may also detect and track the position of aline-of-sight infrared beacon or beacons powered by one or more externaldevices. In an embodiment of the invention, a wide spot NorthStar® pointsource infrared LED 139 a may be located on the robotic cleaner incombination with the NorthStar® sensor 139. The refection from the widespot NorthStar® point source infrared LED 139 a as measured by theNorthStar® sensor may provide information about the environment such asproximity and direction to walls, furniture and other large objects. Inan embodiment of the invention, a narrow spot NorthStar® focusedinfrared LED 139 b may located on the robotic cleaner in combinationwith the NorthStar sensor 139. The reflection from a narrow spotNorthStar® point source LED 139 b as measured by the NorthStar® sensormay detect when the robotic cleaner is driving under low hangingsurfaces such as chairs, beds, sofas and tables. In an embodiment of theinvention, the sensor readings from the wide spot LED 139 a and/ornarrow spot LED 139 b may be used to identify specific locations withina room or area of a home either by the value of the measurementsthemselves, or in combination with other sensory data relative to alocation within a room or area of a home.

FIG. 14 illustrates an embodiment of a robotic cleaner according to anembodiment of the invention. The robotic cleaner 140 includes a mainrobot body 141 and a cleaning module 142. The main robot body mayinclude the drive system and chassis, the navigation sensor and controlelectronics, the user interface, a handle and a docking connection. Thecleaning module 142 may includes a cleaning cloth, pad or othermaterial, which is applied to a floor surface. In this embodiment of theinvention, the cleaning module 142 carries the batteries. The cleaningmodule 142 may mount to the robot chassis. In some models of the roboticcleaner, the cleaning module 142 is detachable and may be swappable withother cleaning modules having other cleaning functions.

FIG. 15 illustrates a three quarter view of a robotic cleaner accordingto an embodiment of the invention. The robotic cleaner 150 includes amain robot body 151, a universal joint with quick release option (notshown) and a cleaning module 152. The main robot body 151 and cleaningmodule 152 are similar to the embodiment illustrated in FIG. 14. Theuniversal joint attaches the cleaning module 152 to the robot chassis.In an embodiment of the invention, the universal joint allows a degreeof freedom for the cleaning module 152 to follow the floor surface. Theuniversal joint provides a detachable option on some models of therobotic cleaner so that the cleaning module 152 may be switched out withanother cleaning module with different cleaning functions. The universaljoint may also connect power from the batteries to the main wiringharness in the main robot body 151 in an embodiment of the inventionwhere the batteries are located within the cleaning module 152.

FIG. 16 illustrates examples of different cleaning modules for the mainrobot body. Cleaning module 162 is a cleaning module with a motorizedsweeper brush and dust bins. Cleaning module 163 includes an extra-widecleaning pad which may be utilize for wet mopping or dry mopping.Cleaning module 164 includes a cleaning solution well, a sprayer ordispenser, and an absorbent cleaning pad.

FIG. 17 illustrates a side exterior view of a robotic cleaner accordingto an embodiment of the invention. The robotic cleaner 170 includes ainternal power supply and motor control 171, a rear handle 172, a drivesystem 173 including wheels, a main robot body 174, an assembly 175including a primary sensor and CPU and a cleaning module 176. Thecleaning module 176 is similar to the cleaning module 142 in FIG. 14.The assembly 175 includes software installed thereon into a memory,which when executed, controls navigation and cleaning behaviors.

FIG. 18 illustrates a side cut-away view of the robotic cleaner withcovers removed according to an embodiment of the invention. The roboticcleaner 180 includes a power supply and motor control board 181, a robotframe and chassis 182, an assembly 183 including a primary sensor andCPU, a cleaning module 184 and a universal joint with quick releasemechanism 185. The cleaning module 184 is similar to the cleaning module142 in FIG. 14. The universal joint 185 includes functionality asdescribed in FIG. 15. The assembly 183 including the primary sensor andCPU includes functionality described above in FIG. 17.

FIG. 19 illustrates a top view of a robotic cleaner according to anembodiment of the invention. The robotic cleaner 190 includes a cleaningmodule 192, a protective gasket/skirt 193 and a main robot body 191. Theprotective gasket/skirt covers 193 gaps between the robot body 191 andthe cleaning module 192, while allowing the cleaning module 192 to pivotand tilt with the floor surface.

FIG. 20 illustrates a top view of a robotic cleaner with a cover (orshell) removed according to an embodiment of the invention. The roboticcleaner 200 includes a power supply and motor control board 201, anouter shell 202, an inner frame and chassis, a left-right wheeldifferential drive system 202, a wheel assembly 203, a main controlboard 204, battery bays 205 and proximity sensors 206. The roboticcleaner 200 includes a cleaning module 207 which is similar to thepreviously described cleaning module 142 in FIG. 14. The power supplyand motor control board 201 connects to a main harness for data andpower. The power supply and motor control board 201 may also support (orinterface) with an external charging port. The wheel assembly includes awheel 203 w, an axle 203 a, a gearbox 203 g, a motor 203 w and anencoder 203 e. The main control board may 204 include a Northstar®sensor 204 n, a PCB with a main CPU 204 p, program selection button(s)204 b, and indicator lights 204 l.

The cleaning module 207 may house left and right battery bays 205. Theproximity sensors 206 may be an option and may be utilize for forward,side and downward views.

FIG. 21 illustrates a back view of a robotic cleaner with a coverremoved according to an embodiment of the invention. The robotic cleanerillustrated in FIG. 21 includes user interface buttons 211, a NorthStarsensor 212, an inner frame and chassis 213, a left-right wheeldifferential drive and a drive system 214. The drive system xxx includeswheels 214 w, an axle 214 a, a gearbox 214 g, a motor 214 m and anencoder 214 e.

An embodiment of the invention may include a robotic cleaner and adocking station according to an embodiment of the invention. The dockingstation may include a NorthStar® Room Projector, a foldable ramp, a padremoving strip, a used pad storage well, a secondary navigation beaconand charging connectors. The pad removing station takes used pads off ofthe cleaning module of the robotic cleaner. The charging connectors maydock with a rear section of the robotic cleaner.

FIG. 22 illustrates a robotic cleaner with optional sensors according toan embodiment of the invention. The robotic cleaner 220 may include reardrop-off sensors 221, which are located on the rear of the main robotbody 222. The rear drop-off sensors 221 may protect the wheels frombacking off an edge of a surface while turning or travelling in areverse direction. In an embodiment of the invention, the optional reardrop-off sensors may be built into the main robot body shell. Therobotic cleaner 220 may include a retractable sensor/bumper 223, whichis mounted on a side (or both sides) of the cleaning module. The sideretractable sensor/bumpers 223 extend over and edge of the cleaningmodule 224. When the side retractable sensor/bumper 223 senses or hits awall or obstacle, the side retractable sensor/bumper 223 retracts overthe cleaning module 224 to allow for full reach to the wall and thus forcleaning to the wall.

The robotic cleaner may also include a front mounted retractable sensorbumper or bumpers 225. FIG. 22 illustrates a left front retractablebumper 225 and a right front retractable bumper 226. The right frontretractable bumper is illustrated in the retracted position by thedotted line 227. The front retractable bumpers 225 and 226 retractsbehind a front edge of the cleaning module 224 when in contact with awall or obstacle. The robotic cleaner may also include a drop off sensormounted on the cleaning module 224. The front drop off sensor may detectedges, stairs and other drop-off conditions that are to be avoided. Thefront drop-off sensor 228 may be located on a retractable sensor/bumper225, 226 or 223 (as illustrated in FIG. 22) and may retract out of theway when the retractable bumper makes contact with a wall or objects.

The following section describes the design and functions of cleaningrobot platform. This robotic cleaner platform can executed in a varietyof embodiments, which include but are not limited to: a cleaning robotwith a single purpose cleaning mechanism, a single cleaning robot withtwo or more cleaning mechanisms, and cleaning robot which is compatiblewith a variety of detachable cleaning accessories, or a combination ofthe above. An embodiment of a robotic cleaner shown as an example inincludes:

1) Front cleaning module for holding a cleaning material directly to thefloor surface (such as a disposable cloth or pad) where the module maybe attached to the main chassis of the robot, with or without a flexiblejoint to allow maximum contact with the floor.

2) A battery pack located in the front cleaning module to provide powerto the robot, as well as level apply weight to the cleaning module tofor increase the amount of pressure applied to they floor surface bycleaning cloth or pad

3) Two powered wheel assemblies connected to the robot chassis (with orwithout suspension) position behind the front cleaning module

4) A main chassis holding all of the components together

5) A NorthStar® positioning sensor placed near the front cleaning moduleto provide positioning information

6) A main control board with microprocessor, memory and I/O into all ofthe electrical components for controlling the robotics functions andbehaviors

7) Software that runs on the microprocessor to perform all functions andbehaviors

8) Wheel or motor encoders that track the movement of each wheel on therobot and use that information to help control its path and calculateits movement

9) Circuitry that enables the microprocessor to measure the current ofthe motors, as a means of detecting when the robot has made contact withan obstacle through some part of its shell without the need for amechanical bumper, proximity sensor or other electronic device (althoughthose systems could be optionally employed)

10) A shell that covers the body of the robot

11) Buttons, lights and/or other means of user interface that enable theuser to turn the robot on and off, select programs and understand itsstatus

Additional sensors may integrated with the robot based on the desiredfunctionality, which is described in more detail below.

The robotic cleaner may include additional modular options. Additionalmodular options for an embodiment of the robotic cleaner may include butis not limited to:

1) Detachable wheels for changing to different drive surfaces.

2) Sensor modules for adding additional components.

3) Detachable and/or updatable main processor and/or memory for updatingthe cleaning programs and capabilities of the robot.

4) Detachable front cleaning module, that is connected by a mechanicalrelease, magnetic connection, electrical connections and/or othermechanisms to provide the user one or more functions, which may includebut are not limited to:

a) Enabling the user to detach the cleaning module from the robot bodyto make it easier for the user to clean the module and/or change outcleaning materials used in connection with the cleaning module, such asa pad, cloth, sponge, brush, canister, solution and/or other cleaningcomponent, and then reattach the cleaning module to with refreshedmaterials.

b) Enabling the user to detach the cleaning module and reattach themodule in an alternative position or positions, to adapt the cleaningmodule for different tasks and/or surfaces, and/or make more efficientuse of the cleaning materials. One embodiment includes is not limited toallowing the user to turn the cleaning module 180 degrees so that thecleaning surface that was facing the rear of the robot is now facing thefront, for cases where dirt and/or other material may tend to build upon the forward most area of the pad.

c) Enabling the user to detach the cleaning module to plug it into acharging device to recharge the batteries, without having to connect theentire robot.

d) Enabling the user to detach the cleaning module to replace it witheither a new but similar replacement cleaning module and/or replace itwith a functionally different cleaning module that is compatible withthe robot body, but provides additional and/or different capabilitiesfor cleaning. Embodiments of these accessories include but are notlimited to:

i) a cleaning module that holds a stationary cleaning material, such asa cloth, pad, sponge or other material.

ii) a cleaning module that may include a powered mechanical cleaningdevice, such as a motorized brush, duster, buffer, vacuum, fluid orsteam cleaning apparatus, motorized pad, cloth or sponge, and/or otherpowered device, either by itself or in combination with another powereddevice, stationary cleaning material, and/or waste collection bin forgather material from the floor.

iii) a cleaning module that may dispense cleaning solutions and/orfluids, apply steam for cleaning, use sprays, foaming solution and/orother dispensable material for cleaning.

iv) a cleaning module that includes an air and/or floor surfacefreshening device. a cleaning module that includes a secondary drivesystem and/or unpowered wheels to provide more support, traction andpayload capacity if needed for the modules' function. a cleaning modulethat uses two or more of the approve systems in combination.

5) Leveraging the ability to have detachable modules for differentcleaning tasks to provide other supporting functions, which can includebut are not limited to:

a) adjusting form factor of the cleaning device to optimize forperformance while maintaining a standard robot body.

b) adjusting the number of batteries or power source located within thecleaning module to match it with the specific requirements of thecleaning mechanism.

including stored software, data, instructions and/or control electronicsin the cleaning module that the robot can utilize to update and/or adaptits available programs to match the functions of the cleaning module.

c) including enhanced sensors, drive mechanism, and/or other systemsthat expand the robot's capabilities and/or enhance its performance.

Some of the robotic cleaner configurations utilize expanded sensorcapabilities. Design executions of the robot and/or cleaning module mayadditional sensor configurations for enhance performance, whereembodiments of the additional sensor configurations include but are notlimited to:

1) The placement of one or more drop-off sensors on the robot and/orcleaning module to detect and help the robot avoid, stairs, ledges andother drop off areas.

2) The placement of one or more mechanical bump sensors on the robot todetect contact with objects.

3) The placement of one or more proximity sensors for measure distanceto walls, objects and/or other obstacles to avoid them without the needto make contact and/or engage in specific navigation and/or cleaningbehaviors such as wall following.

4) The placement of one or more light emitting optical flow sensors toprovide additional measure for relative ground motion and/or provide analternative means for detection drop off areas, detecting when the robothas been picked up, detecting if and/or tracking how the robot has beenmanually moved.

5) The placement of NorthStar signal emitting projectors on the robotitself to utilize NorthStar's capabilities to provide additionalinformation on the surrounding environment and/or expand the operationof the robot, which may include but is note limited to:

a) Detecting when the robot is under a table or other object that may beobstructing its direct view of the main navigation signals from aNorthStar room project.

b) Detecting the presence, proximity and/or general location of wallsand/or other objects.

c) Detecting user gestures through reflection of the projected light offof their body and/or movement near the sensor.

d) Any combination of the above systems.

One option for a design execution of the robot cleaner addresses theproblem of placing the cleaning module, material and/or mechanism in thefront of the robot, to enable it the module and reach all the way towalls and edges around obstacles, while at the same time wanting todetect obstacles and/or avoid falling over edges and stairs. In aconventional cleaning robot, sensor mechanisms are placed in front inmaximize detection of obstacles and hazards. These sensors usuallyinclude a bumper sensor, IR or sonar proximity sensors and/or IRdrop-off sensors. The cleaning mechanism is traditionally placed behindthese sensors, limiting how far it reaches when the robot comes intocontact with a wall, obstacle and/or other hazard.

As an alternative embodiment, a possible design that can be integratedin this base configuration is a retractable drop-off, wall and/orobstacle detection system. This option can be used independently and/orintegrated with the use of other sensors placed in other locations ofthe robot, such as on the sides and/or the back of the robot to provideadditional capabilities and/or protection. This system can consist ofbut is not limited to the following design:

One or more bumpers than extend over the front edge of cleaning moduleand/or over the sides of the cleaning module, where the bumpers retractover the cleaning module and/or get pushed in (such as through a springand/or other tensor mounted mechanism) when they come into physicalcontact with wall, object and/or obstacle, and return to their neutralposition when the robot moves away from the obstacle.

Where when pushed in, the bumpers allow the cleaning module andassociated cleaning material and/or mechanism make full contact with thefloor to the edge of the wall, objects and/or other obstacles, and/or ifneeded, may make contact to clean the vertical base of the wall and/orother objects as well.

The bumpers include one or more sensors that, when the bumpers areextended, the sensors can see past the edge of the cleaning module andbe used for one or more of the following tasks, which include but arenot limited to:

1) Drop-off detection to prevent the robot from driving over a ledgeand/or down the stairs through the use of one or more sensors focused onthe floor area in the path of the robot.

2) One embodiment can include but is not limited to where the drop-offsensor or sensors can also be used to detect if the robot has beenlifted off from the ground and change its operation mode accordingly.

3) Motion tracking, where one or more optical motion tracking sensorsdirected toward the floor, which can track the robot's movement over thefloor surface.

4) One embodiment can include but is not limited to a system that has atleast two sensors, mounted on opposite sides of the robot to track boththe forward and backward motion, but also the turning motion of therobot. This information can be used independently when the otherpositioning information is not available to estimate the robots'location and/or can be fused with information from other positioningsensors and navigation systems to enhance the estimate of the robots'position.

5) Embodiments of the sensor system can also include the function butnot be limited to where the same sensor or sensors can also be used todetect if the robot has been lifted off from the ground and change itsoperation mode accordingly. Obstacle detection in the path of the robot,such as for travelling forward and/or turning.

6) Wall and side object detection, enabling the robot to align itself towalls and/or other contours formed by objects and engage in classic wallfollowing behaviors, which can include but are note limited to:

7) Cleaning along the edges of walls

8) Cleaning along the perimeter of furniture and other objects

Aligning its systematic path to the outline of walls and barriers in aroom, where one embodiment can include but is not limited to thepatterns shown in FIGS. 1-7 earlier, where the robot aligns part or mostof its be parallel to the main boundaries of the room or area.

9) Engaging in perimeter following behaviors to navigate back to anotherlocation in a room when position information is not available orreliable.

10) Mapping the boundaries of the room and/or area.

11) Beacon and/or other object detection that can be used to help therobot dock and/or perform operations which require the robot to alignthe cleaning module to another device.

12) One embodiment can include but is not limited driving onto a dockingramp and stopping over a specific area marked with a pattern and/orreactive material, where the placement of the robot in that location onthe ramp is part of performing a maintenance, self-cleaning and/or otheroperational function.

13) Bump detection, where the change in position of the bumper orbumpers provides indication of contact with a wall, obstacle and/orobject.

Embodiments can include but are not limited to contact switch mechanismswhich detect the change in position and/or retraction of the bumper.

Other embodiments can include but are not limited to use of the functionof the integrated sensor, to detect that the bumper has been pushed in.Examples include using the change in readings from an edge detectionsensor, proximity detection sensor, motion tracking sensor and/or othersensor to detect that the sensor is in the retracted position, as wellas any combination of the above approaches.

Where the placement of the bumpers and integrated sensors in the neutralposition provides for protection of having the robot go too far over anedge before being able to correct its path. Embodiments of this sensorsystem can include but are not limited to:

1) Placing sensors capable of edge detection either in parallel with theouter most point of the rear wheels (measured from the perpendiculardistance from the center axis that travels back to front through therobot), or extended further out to the sides than the wheels are.

In an embodiment of the invention, the cleaning module is designed to bewider than the wheel base, so sensor placement could either be on thesides of the cleaning module, and/or on the front leading edge on theleft and right sections of the cleaning module that extend past thewheel base.

Another embodiment for drop-off detection can include but is not limitedto having the drop-off sensor built into the underside of the cleaningmodule in the desired regions needed to protect the robot from fallingover edges and/or down stairs, but modifying the sensor design to workin the specific conditions of the cleaning mechanism, such as being ableto function when covered by a cleaning pad, cloth or other material.

In one embodiment where the robot has a cleaning cloth or pad attachedto the base of the cleaning module for cleaning floors, the drop offsensors could project a signal through the cloth or pad material, and becalibrated to account for the disruption of the signal passing back andforth through the material, and using a range of thresholds, detect whenthe sensor was travelling over a drop-off area. This calibration couldbe pre-calculated and/or dynamically adjusted based on environmentalconditions and/or the specific material used for the cleaning task. Inone embodiment, this could be performed as an auto diagnostic, which mayor may not involve having the robot drive around to calibrate, and/orhaving the robot travel to controlled environment such as on a basestation, that allowed it to calibrate thresholds for the presence and/orabsence of contact with the floor. Another embodiment can include but isnot limited to using the sensor readings to also assess the amount ofdirt and/or other material built up on the cloth or pad, and/or theamount of dirt and/or material being picked up in a specific areas ofthe floor, in order to enhance the robot's cleaning performance and/orprovide user feedback.

Additional embodiments of robotic cleaners may include different productconcepts or design elements that can be use used in combination withsystematic and/or non-systematic localization systems to enableintelligent cleaning. The range of possible embodiments includes but isnot limited to the concepts, functional elements and/or design elementslisted below, or combinations thereof.

Key Functional Attributes may include low-cost mobile robots, eachdesigned for a specific cleaning task or select set of task (simple buteffective cleaning mechanisms & accessories), which are fast, agile,lightweight, quiet and have super smart navigation and control systemfor systematic cleaning

The design attributes may include an open/organic design. Aspects of therobotic cleaning device should echo the functional elements of everydayhousehold cleaning products and appliances to help communicate purposeand function to consumers. FIGS. 23-28 provide popular reference pointsas cases of common cleaning products according to the prior art.However, each robot needs to incorporate and emphasize significantlyevolved robotic/functional features that clearly distinguishes theproduct and conveys elements of its intelligence and autonomouscapabilities.

Additional design attributes may include that 1) the robotic cleanershould appear much less bulky than existing robotic cleaning products onthe market, such as Roomba® (less mass); 2) the robotic cleaner be muchmore sportier, faster, agile, (e.g., if Roomba® is a minivan, the robotsdescribed herein are sports cars); 3) it is ideal for the roboticcleaner to stay low to the ground for clearance and reach; and 4) thatthe active cleaning function for each robot is a “hero” feature (takesprominent focus).

For effective coverage, the robot may need to be as large as 10 to 12inches in width for medium-scale robots. Small-sized robots wouldemphasize speed and ability into tight spaces. The drive system for therobotic cleaners may be placed in rear, an should feel smaller inproportion (e.g., have a narrower footprint). The drive system may haveeither two rear wheels or two tank treads that fit within the curvedboundary. The drive system of the robotic cleaner may be driven byoff-the self batteries (e.g. 4-8 AA) and may be rechargeable.

Structure can extend on sides to provide part of forward structure aswell (fenders)—such as for mounting stair and wall detection IR sensors.Some designs of the robotic cleaner may connect front and back on someof the robots with flexible joint/swivel, e.g. for reaching into cornerswith the pad cleaner. Any external edges of the robot made of solidplastic should be curved to avoid catching on objects as robot turns.The robotic cleaner may have ways for front cleaning devices to beflexible, at least on leading corners, e.g., making the ends forcleaning pad holder be flexible rubber so the pad lifts up as it rubsalong something

Other components of the design for a robotic cleaner may include: 1)NorthStar navigation sensor would go on high-point on top of drivesystem; 2) the robotic cleaner has power leads for docking withrecharging station, which are most likely towards rear of chassis, andpossibly underneath.

FIG. 23 illustrates a manual floor cleaning device with rotating brushesas a cleaning mechanism according to the prior art.

Medium-sized robots or robotic cleaners may include, but are not limitedto: a floor sweeper, a dry pad cleaner, a web pad cleaner, a combinationvacuum with dry pad cleaner, a robotic floor polisher/buffer, and arobotic floor scrubber.

The Floor sweeper may include a rotating brush with rear bin. The floorsweeper is:

1) Designed for 1^(st) level of cleaning

2) Brushes up dust bunnies, pet hair, small debris

3) Designed to work on hard wood floors, tile floors and short lengthcarpeting

4) May or may not have cloth or pad to be used in combination with thesweeping mechanism, where brush can be placed in front with the cloth orpad grabbing remaining dirt

Two executions of the floor sweeper may be implemented including ahorizontal roller brush or two counter rotating brushes.

F1: The Horizontal roller brush includes features such as:

1) Can incorporate front roller brush, that may or may not extend beyondthe frame of the robot (show one with exaggerated size to emphasizefunction)

2) Extend beyond the frame would improve reach for getting to the bottomof walls and underneath furniture

3) Apply a lot of surface area contact where ever they reach

4) Roller brush could be disposable or reusable and/or washable

5) Robot chassis and drive system exists behind the brush in onescenario

6) Semi-circular rear body is probably the most pragmatic fornavigation, but a more square-like shape can be an option.

F2: Two counter rotating brushes (street cleaner style) configurationmay, as in F1, include a brushing mechanism that can extend beyond thesides for the robot for maximum reach.

Accessories for the floor sweeper include:

F3: A Docking station which may:

1) Recharges batteries

2) Empties dust bin into larger stationary container (such as havingvacuum in station)

3) Vacuum can also self clean the duster brush or brushes.

F4: One embodiment can include but is not limited to:

1) The duster robot drives into the dock. (e.g., maybe backs in). Itcradles under a nozzle that goes right over a port at the top of thedust bin—which lets the station suck out the dirt from the dust bin intoa larger container.

2) The docking station may be designed so that the robot could alsodrive forward into the dock, and use the vacuum to clean the brush aswell.

3) If there is a cloth or pad, some sort of catching mechanismunderneath on the docking station right below the cloth or pad. When therobot reverses out, the dirty pad gets pulled off and then the vacuumsucks that into the storage bind as well.

Another medium robotic cleaner is a dry pad cleaner for hardwood andtile floors. The dry pad cleaner may include features such as:

1) Designed for 2^(nd) level cleaning

2) Uses cloth-like pad for collecting smaller particles, dirt and dust

3) Should include some forward feeler/bumper for detecting and avoidingdriving onto carpet

There may be three executions of the dry pad cleaner:

D1: A first design is a Basic design with single fixed pad on front

1) This design looks like mop with drive mechanism behind

D2: A second design includes the same rear chassis but withauto-changing pad multiple pads on roller/belt mechanism

D3: A third design puts a Swiffer® pad underneath the body robot, sothat it picks up the dirt the roller misses.

1) If it was on the square version, it could go towards the back—withthe wheels in the middle.

2) Building on that approach, one idea would be to let the user load asmall stack of pads into the back. (maybe 5 or 8 in a spring loadedtray—that's mounted upside down) That way they can just pull out a dirtyone and have a clean one underneath ready to go. (or make removalautomatic at the docking station). If there is a stack, can showcasethat by having the side or rear corners transparent as well, where theuser sees the stack and how many are left.

Accessories for the dry pad robotic cleaner may include:

D4: Drive-on docking station elements and option

1) Low ramp-based shape—robot drives in and up, backups to exit

2) Recharges batteries

3) Static brushes catches extra bits of dust from cleaning pad and dropsdebris in bin (such as when robot drives on and exits off)

4) For robot with multiple pads, can grab and tear dirty pad off toexpose clean one. Mechanisms can include: a) Mechanism on dockingstation that has teeth or other elements that grab and pull the pad offwhile the robot is parked on the station (which can be driven by its ownmotor, or powered by the wheels of the robot when it is parked on thedocking station; b) Static and/or retracting directional teeth or othergripping elements that are built into the docking station, designed toallow the robot drive up onto the station, and then engage and hold thecloth or pad when the robot backs out of the docking station; c)Automatic pulling and/or flipping mechanism for moving the dirty clothor pad out of the way and/or into a storage area, to make room for therobot to repeat the process when the next dirty cloth or pad needs to beexchanged

5) Alternatively, the docking station and robot can be designed so therobot can push the dirty cloth or pad into a storage/waste bay once thepad is removed, where one embodiment can include but is not limited tohaving the robot back out, turn and back into the docking station, wherea bumper or edge provides a surface on the robot for shoveling the padoff the docking station and into a storage bay.

FIG. 24 illustrates a Swiffer sweeper in its packaging and also thecleaning pad assembly of the Swiffer Sweeper according to the prior art.

The robotic cleaner may also be a combination vacuum with dry padcleaner for cleaning hardwood and tile floors. The combination vacuumwith dry pad cleaner is:

1) Designed for 1^(st) and 2^(nd) level cleaning

2) Uses vacuum to get larger debris first

3) Uses cloth-like pad for collecting smaller particles, dirt and dust

One execution of the combination vacuum with dry pad cleaner is: V1:Combination of design D1 of the dry pad cleaner with a vacuum in frontof pad

FIG. 25 illustrates a Swiffer® SweeperVac® according to the prior artwhich is a combination vacuum with dry pad cleaner.

The medium sized robotic cleaner may also be a wet pad cleaner for hardsurface floor. The wet pad cleaner is:

1) Designed as alternative for mopping

2) Different floor surfaces would have different cleaning solutions,such as:

3) Kitchen and bath tile cleaner

4) Hard-wood floor cleaner

There may be two executions of the wet pad cleaner:

1) W1: Absorbent pad with on-board sprayer with a single pad design thatincludes cleaning solution stored in on-board reservoir (or swappablebottle). This design includes a forward spraying jet that dispensessolution. This design also should include mechanism to preventaccidental spray on carpet/on to wall, over edge of floor (e.g.embodiment could be to have low feelers or an extended bumper in frontof pad to detect for changes in the floor surface.)

W2: Same concept as design W1, but with auto-changing pad

W3: Similar concept as designs W2 and W1, but with a steam basedcleaning system integrated to help loosen more dirt and other targetmaterial from the floor which, depending on temperature and the heatedsolution used, helps kill germs and/or sterilize the surface, plusre-absorb dirt, material and fluid from floor surface through absorbentpad material, a suction device, and/or other means. Accessories for themedium sized wet pad cleaner may be:

1) W4: Drive-on charging, drying station. The basic implementation couldbe similar to dry pad cleaner accessory D3, but with drip pan underneathfor catching any excess wetness & letting pad(s) dry out after cleaningis complete

2) W5: Mini tower beacon that is used to set boundary for cleaning area(such as at the boarder at a doorway). This may be a tall, thin freestanding device that could look something like a street light fixture/orvery thin desk lamp. This may be 12 to 18 inches tall, with top forplacing two diodes about 8 inches apart (could be U shape with twovertical posts, or T shaped)

FIG. 26 illustrates a Clorox Ready to Go Mop according to the prior art.FIG. 27 illustrates a Swiffer® Wet Jet® according to the prior art.

An embodiment of the invention may be a robotic floor scrubber which isdesigned for deeper wet cleaning of durable hard surface floors(especially kitchens and baths). One execution of the robotic floorscrubber is:

S1: A robotic floor scrubber may be a combination of wet padauto-changing pad (W2) with scrubbing brushes in front. Robot sprayscleaning fluid in front and systematically scrubs back and forth. Therobot wipes up area & soaks up solution with pad. One embodiment wouldbe to have pads on other end of robot—where robot turns 180 degrees andgoes over area with its pad. An alternative embodiment is to havescrubbing mechanism to be relatively compact and placed just in front ofpad, so robot absorbs cleaning solution as it drives forward

Another embodiment of the medium robotic cleaner may be a robotic floorpolisher/buffer which is designed as finishing step as means for addingprotective coating/enhancing shine of hard floor surfaces

One execution of the robotic floor polisher buffer may include:

1) B1: Floor unit with high speed buffing pads. The buffing pads may beeither a pair of counter rotating pads (like F2 configuration) or otherdesign (such as horizontal rollers with pads wrapped around them). Therobotic floor polisher/buffer includes waxing, polishing liquidreservoir and spray dispenser and soft pads that both polish and absorbexcess liquid.

There also may be micro robotic cleaners which are smaller than themedium robotic cleaner. In other words, micro robots are small robotsfor smaller tasks. The micro robots may be half to one third the size ofmedium-scale robots. The micro robots may have different configurationof NorthStar®, where the sensor is placed in center base unit andbeacons are on the robotic cleaner. The micro robot may or may not needto auto-dock. Examples of the micro robots include, but are not limitedto:

Table Top Robotic Cleaner

The table top robotic cleaner may be designed to clean up dinningtables, coffee tables, small floor areas (e.g. spot cleaning).

One execution of the table top robotic cleaner includes:

T1: Mini version of F1 or F2 (rotating brush and bin) for collectingcrumbs, etc. with a pad added

1) Has edge detection to keep from falling off the table

2) Small pad would provide for cleaning/dusting/polishing

Mini Wet Floor Robotic Cleaner

The mini wet floor robotic cleaner is designed to clean up smallbathrooms, spots in kitchen or spills. The mini wet floor roboticcleaner gets in corners and behind things.

Two executions of the mini wet floor robotic cleaner include:

MW1: Simple wet pad cleaning robot

1) Pad is most likely in fixed position (non-changing)—almost like a wetpad version of D1

2) Flairs up on sides of pad to clean along walls and other edges as itdrives

MW2: Mini version of S1 (scrubbing brushes) but without sprayer

1) The cleaning robot just has brushes and an absorbent pad

Other accessories for the mini wet floor robotic cleaner include:

MW3: Portable cleaning base station.

1) Base station holds warm water, cleaning solution, and reservoir forcapturing during water

2) Robot drives up and base station rinses out pad and applies freshsolution on to pad

3) Base station has NorthStar®, tracks the position of one or morerobots

4) User should be able to pick base station up by handle and plug itinto the wall for recharging when needed

Mini Dry Floor Robotic Cleaner/Duster

The mini dry floor robotic cleaner/duster is designed to get into hardto reach places (behind furniture) and cover corners and base boards

Two executions of the mini dry floor robotic cleaner/duster:

MD1: Brush based cleaner. The brush based cleaner:

1) Has rotating brushes that get at both the floor and sides (such asbase boards)

2) Could include a pad or disposable duster material

3) Has tank drive and streamlined design to avoid getting hooked oncords or stuck on things.

4) Can incorporate front roller brush, that may or may not extend beyondthe frame of the robot cleaner (show one with exaggerated size toemphasize function)

5) Extends beyond the frame would improve reach for getting to thebottom of walls and underneath furniture

6) Applies a lot of surface area contact where ever they reach

7) Roller brush could be disposable or reusable and/or washable

8) Robot chassis and drive system exists behind the brush in onescenario

9) Semi-circular rear body is probably the most pragmatic fornavigation, but a more square-like shape can be an option.

FIG. 28 is a Swiffer® Scrubmagnet® device according to the prior art.

The goal of the navigation system described in this invention is toprovide the full benefits of systematic cleaning in unstructuredenvironments, but at a significantly lower cost to make the productsaffordable to the mass consumer market.

In an embodiment of the invention, this goal is achieved by cleaning ina region by region approach, where the robot systematically cleans onesection of a room or an area of a home at a time though the use of alocal map and local sensory position system, and then moves on to cleanadditional regions. The reduced size of the region allows for lower costsensors to be used, where the size of the region is set so the robot isable to track its position through the region before the normalaccumulation the noise and drift from the sensors causes the robot tolose its position.

In an embodiment of the invention, the system supports the use of dryand/or wet consumable cleaning cloths, where the regional cleaningapproach enables the robot to use of the cloth to clean in a evenprogression through the room, so that if the user changes the clothduring the cleaning process, the fresh clean cloth is generally used toclean new areas of the floor, as opposed to clean areas already covered.

In an embodiment of the invention, the robot uses a global positioningsystem in combination with the local positioning system, to arrange theregions to ensure good overall coverage of the room or area of the home,so that target areas set by the system are reached. As with the localpositioning system, the sensors for the global positioning system arecost optimized so that the range, accuracy and reliability of the globalsystem is effective enough for being able to provide adequate overlap ofthe local regions, but is not required to maintain highly accurateglobal position by itself throughout the full room or area of the home.

These functions are accomplished by using a cleaning strategies andsoftware algorithms that work with a unique combination of low costsensors and components.

In an embodiment of the invention, the combination of sensors andcomponents includes any or all of the following elements: a low costIR-base global localization sensor mounted on the cleaning robot; a lowcost IR projector built as a separate physical device from the robotwhich projects an IR light spot (or spots) which the robot can detect;wheel tachometers which are connected to the drive motors of the robot;motor current sensing connected to the drive motors of the robot forsensing when the robot has contacted obstacles through feedback detectedin the resistance on the wheels; and a gyroscope mounted on the robot.An example of the NorthStar® system and its potential functions isdescribed in NorthStar patent application Ser. No. 11/090,621, filedMar. 25, 2005, Additional capabilities and configurations are alsodescribed in Robotic Game patent application Ser. No. 12/234,565, filedSep. 19, 2008.

The system may include a variety of configurations for the IR projector.Embodiments can include but are not limited to a battery powered unit, awall pluggable unit, or a combination of a wall pluggable unit which isalso battery operated. The projector has one or more IR LEDs thatproject IR spots on the ceiling which the NorthStar sensor can detect tolocalize its position. In an embodiment of the invention, the projectormay have three, four, five, or more spots at different frequenciespointed at different directions to expand the range for detecting thesignal, where the sensor may also localizes on at least the two of thespots to determines its location. Utilizing this approach, the sensormay select different spots which provide better location information,such as by selecting spots that have an optimal orientation relative toits position for calculating the robots location, and/or selecting thespots based if their signal intensity to provide for the best signal tonoise ratio. In an embodiment of the invention, two or more IRprojectors may be used to expand the range of coverage by projecting IRspots at different IR frequencies in different areas of the room orhome, including but not limited covering different rooms or areas in thehome to enable room-to-room cleaning and navigation.

In an embodiment of the invention, the cost of sensors and components isso reduced that none of the sensors or components provide enoughreliable information by themselves to provide the full solution, butwhen used in combination with each other and the cleaning strategy, theoverall system can deliver system cleaning that is far more effectivethan random cleaning robots, and as effective or more effective as morecomplex and expensive navigation systems.

Alternative sensors may be used in alternative embodiments, which mayinclude but are not limited to: accelerometer for another means ofdetecting with the robot has made contact with obstacles; IR proximitysensors for detecting obstacles and following along walls and obstacles,drop sensors for detecting if the robot is about to go over a ledge,and/or other sensors that may support the navigation of the robot, suchas referenced herein.

In an embodiment of the invention, the local cleaning behavior can beimplemented in the following configuration. The robot uses a gyroscopeand wheel tachometers to track its location within a local map of theregion, where the tachometers enable the robot to plot its position onthe map based on distance travelled, and the gyroscope enables the robotto correct for the drift in tachometry as the robot turns to providebetter accuracy of the robot's direction and position in the local map.Detection of obstacles and other location-based sensory information maybe included in the local map for us in plotting areas to clean, pathplanning around obstacles, exploring for new regions and uncoveredareas, and closing off areas marked as completed.

In an embodiment of the invention, the robot initially cleans followinga rank pattern of parallel rows progressing across the room in onedirection. The robot utilizes the gyroscope to make even 180 degreeturns and maintain the parallel orientation of the rows, where the angleis close enough between rows so that the rows overlap and minimize anygaps not covered between the rows. As the robot turns from one row thenext row, the alternation between left and right turns helps counteractinternal gyroscope drift and extend that pattern for a longer period oftime (and thus larger area.) The robot uses wheel tachometry formeasuring the length of the rows, and with correction from the gyroscopeand detection of obstacles from other sensors, builds a map of theregion.

In embodiments of the invention, the robot may be programmed to cleanalong a row and then turn onto the next row until one or more eventsoccur, which may include: reaching an obstacle; reaching a maximum rowlength; attempting to follow around an obstacle or obstacles until therobot has travelled a minimal amount of distance along the row;attempting to follow around an obstacle or obstacle based on theposition relative to the prior row; attempting to follow around anobstacle until a maximum number of obstacles are hit; and/or reachingand end boundary of the target region with the robot's internal localmap.

In an embodiment of the invention, the robot can make a full sweepthough the region, and then use algorithms that identify areas that havenot yet been cleaned in the local map to have the robot navigate tothose areas and clean them and update the map while localization isstill reliable. The robot may also close of any frontiers determined tobe blocked by obstacles as non-cleanable areas. Boundaries along theperimeter of the cleaning region which are not blocked off by obstaclesmay also be stored on the map and used later in determining adjacentregions to clean.

In embodiments of the invention, the robot sets limits for the maximumlength of the rows and the number of rows allowed within a region soattempted area of coverage stays within the tolerance allowed foraccumulated error and drift from the combined readings and correctionsof the sensors. The limits can be set through a number of means, whichinclude but are not limited to: fixed value for either the length of therow and/or the number of the rows; a dynamic setting to one or both ofthe dimensions based on the environment, such as if the robot detectsthe cleanable area to be narrow and wide, and thus able to be completedwith more rows, but at shorter lengths; a measure of time or areatravelled; and/or though feedback on the sensor drift through comparisonof the values with other sensors, where the cleaning region size growsuntil the accumulated error reaches a threshold.

In an embodiment of the invention, once completing one region, the robotwould re-localize its position using readings from the globalpositioning system (e.g. Evolution Robotics' NorthStar positioningsystem) and then plan the location for the next regional area ofcleaning. This processing may include uploading data from the locallymapped area in the region to a global map, which fills in as the robotcleans more regions in the room.

In an embodiment of the invention, the global positioning system maytrack the progress of robot while it is cleaning the local region as aparallel process. In cases where the global positing system isdetermined to have a minimal level of reliability for that region, gapsof a certain size found in the global map may be copied down onto thelocal map to have the robot revisit and re-clean those areas if neededto provide for redundancy in the system.

In an embodiment of the invention, re-localization may be accomplishedthorough a number of means in cases where access to reliable globalposition information is limited or not immediately available at therobot's current location. An example may include but is not limited toreturning to a specific reference point (or one of many availablereference points) where the robot can re-calibrate its position, plotthe target location for the next cleaning region, and drive to thatregion to begin the next regional pattern. In the case where the globalpositioning system is used, the robot homes on the signal provided fromthe global positioning system until it reaches an area where it can plota course to a reference point.

In the minimal case, the reference point may be in close range to acharging station or some other form of “home base” for the robot to useas starting location. The robot may use one or more emitted signals tohome back to the charging base, and if needed, position itself relativeto the base where its position and orientation are estimated to be at ahigh confidence level.

In an embodiment of the invention, the robot may also re-localize usinginformation from the gyroscope, odemetery and other sensors are used totest for the reliability of a global positioning system, to dynamicallydetermine when the global system is providing accurate enoughinformation on which to re-localize. As one example, the local sensorsprovide readings for several samples over a certain time, and when thechange in the global position reading matches the estimated change fromthe local sensors, then the robot can re-localize. As a fall backmethod, the robot may use the global localization system to return to a“safe point” where it has high certainty of its relative positionwithout the need for additional or new validation from other sensors.

In an embodiment of the invention, the robot may clean in a regionalmethod using a local map and input from local sensors (gyroscope andtachometers, etc.), and move from region to region without the use ofglobal positioning system either for part or all of its operation duringa cleaning run. In embodiments of the invention, upon the completion ofone cleaning region, the robot may move to a new location to begin a newcleaning region through a number of means, which include but are notlimited to: driving to an estimated location within the existingregional based on the local map and sensors, and begin cleaning a newregion that extends outside the area of the existing cleaning region;driving to an estimated location outside the existing region based onuse of the local sensors to reposition the robot and then begin a newcleaning region; and/or driving to a random location relative to theexisting cleaning region and then begin a new cleaning region.

In embodiments of the invention, a number of techniques can be used toexpand the regional area of cleaning and/or more efficiently organizethe placement of regions based on the environment. In the case of usinga low-cost global positioning system which may have limited range oronly certain patches of coverage in a room, the regional cleaningpattern can be combined with periodic re-localization to allow for theregional pattern to run longer and over a larger area. As one example,if the center area of a room has a good global localization signal (suchas emitted from an IR spot projector or other point source) the robotcan align the cleaning pattern (such as parallel rows) so that the robotis passing in and out of the global area of coverage in the course oftravelling through one or more of the rows (such as on the middle or atone of the ends of the row.) By recalibrating its position when therobot is in the global area of coverage, the robot can essentiallyre-set the drift to zero or some lower value, and rely on the localsensor to continue the cleaning pattern. This process can also beperformed ad hoc, when ever a reliable global position signal is found.

In an embodiment of the invention, strategies for arranging the cleaningpatterns may be used to further improve coverage of the regions and orentire area. As an example of a technique, the robot may do two or morepasses over the same region or set of regions to ensure more thoughcleaning. This may include changing the primary direction of thesystematic pattern between the passes to expose different frontiersbetween the passes and possibly extend into areas missed on the firstpass. Examples may include but are limited to: having the robot cleanthe area in one direction in a single session, and then start over anredo the entire area in a different direction (either perpendicular orsome other angle), where the room or area may be divided into differentregions based the pattern and environment; have the robot do two passesover each region each time the robot is run, in either a perpendicularor other angle; or vary the angle in paired set, so that the robot picka new angle on each cleaning, and then follows with a pass on aperpendicular angle. The benefit of these approaches is that theyadditional passes will likely remove additional dirt in the areas thatare covered more than once—and possibly make the cleaning function workbetter across different grains in the floor surface—while providing muchmore even coverage than a random approach.

In an alternative embodiment of the invention, the regions can be moreflexible and emergent based on the discovered areas. One example mayinclude using mapping to expose open frontiers in global map after thefirst pass of a systematic cleaning pattern. The robot can then use thatinformation to clean into the frontiers, and where new areas arediscovered, repeat the systematic cleaning pattern and frontierselection process.

In any of the embodiments described above, the robot may also useperimeter cleaning (including wall following and obstacle following) toclose off frontiers in the area covered by a systematic pattern, as wellas initiates another area of systematic cleaning in new areasdiscovered. The perimeter cleaning could be done as a process within aregion before the region is marked as finished, as a process acrossregions after multiple regions are visited, or as a combination of bothwithin and between regions based on the size of obstacles found and thelength the robot can travel along the wall without going to far from itstarget location.

New approaches, methods, designs, technologies and solutions forintegrating localization, positioning and navigation systems to providenew and unique benefits and capabilities for mobile robotic-enabledproducts that need to operate in everyday environments. For illustrationpurposes, the specific embodiments described and illustrated in thisdocument are described primarily in the context of mobile floor cleaningrobots, where the benefits and capabilities represent a significantadvance in performance over random, semi-random methods for floorcleaning and/or other methods employed by leading consumer robotic floorcleaning products on the market. A description of possible embodimentsof robotic cleaning devices that could utilize localization, positioningand navigation systems includes but is not limited the products,concepts and designs described in the drawings.

The scenarios described herein using an infrared-based localizationsystem, but may easily be enabled by devices that use other means forlocalization, including but not limited to devices that utilize visualpattern recognition, visible light detection, laser reflection,odemetery, optical navigation sensing, inertial sensing, thermaldetection, motion detection, sound detection, radio wave detection,physical contact detection, proximity detection, magnetic fielddetection, electrical field detection, or any combination thereof. Oneembodiment of an infrared-based localization system would include theNorthStar® system from Evolution Robotics, which is cited in priorapplications, namely U.S. patent application Ser. No. 11/090,621, filedMar. 25, 2005, which is hereby incorporated by reference herein.

For the purposes of these descriptions, the application of localization,positioning and/or navigation systems includes but is not limited to:the ability to determine the position of one or more devices, objects,locations and/or boundaries within a physical space along one or moredimensions; the ability to provide partial information on the relativeposition of one or more devices, objects, locations and/or boundariesfrom one or more other points that is useful in the performance of anapplication; the ability to make estimates of position of one or moredevices, objects locations and/or boundaries that are useful in theperformance of an operation; the ability to guide one or more mobiledevices and/or objects along a planned and/or unplanned course throughone or more physical spaces; the ability to navigate between two or moreobjects, devices, locations, and/or boundaries within a physical spacewhere information on the points between the devices, objects, locationsand/or boundaries may or may not be available; the ability to storeposition information, identification and/or other indication of locationof one or more devices, objects, locations, boundaries, paths, and/orareas of coverage for retrieval and use at a later point in time; theability to map one or more represented locations, devices, objects,boundaries, paths, and/or areas of coverage for use in the performanceof an application; the ability to detect and/or discover positioninformation about one or more physical environments that is used toadapt and/or enhance the performance of one or more tasks within thoseenvironments; the ability to use position information to help identifyand/or classify one or more environments to adapt the performance of oneor more tasks within those environments; and/or the ability to directlyand/or indirectly control one or more devices using the one or more ofthe above abilities and/or other abilities related to localization,positioning and/or navigation.

The implementation of the localization system may take a variety ofembodiments, but can still enable the functions described herein.Examples of embodiments of the localization system include:

1) The placement of a sensor (or set of sensors or integrated sensorysystem) on a robot or robot-enabled device, which enables the robot orrobotic-enabled device to derive relevant position information, whereother objects and/or devices that emit one or more signals may or maynot be used for helping derive position information.

2) The placement of a sensor (or set of sensors or an integrated sensorysystem) on a robot or robot-enabled device, which enables the robot orrobotic-enabled device to derive relevant position information throughpassive and/or active measurements of its environment, throughmeasurement of position by one or more systems at a single point of timeand/or through integration of measurements taken by one or more systemsfrom a series of measurements over time, and/or in conjunction with thecontrol of movements, execution of navigational patterns and/orperformance of location related behavior. One embodiment of thisapproach includes but is not limited to the vSLAM® system from EvolutionRobotics, which is cited through U.S. Pat. No. 7,015,831, filed Mar. 21,2006, U.S. Pat. No. 7,135,992, filed Nov. 14, 2006, and U.S. Pat. No.7,145,478, filed Dec. 5, 2006, which are hereby incorporated byreference herein. Another embodiment can include but is not limited tothe use of one or more proximity sensors in combination with one or morepath following behaviors that guide the movement of the robot orrobotic-enabled device relative to the physical characteristics of theenvironment. One example of this approach would be to have a robot thatincluded one or more proximity sensors that measured distance to walls,objects and/or other fixed boundaries within a setting, and engage apath following behavior where robot followed the contours of the walls,objects and other boundaries in a repeated series of cycles or lapsaround the environment, with the robot initially following the perimeterof the area and shifted its position inward as measured by the proximitysensor(s) upon each completion of a lap, so that it progressively movedto the center of the area until it reached the center and/or coveredmost of the of area within the perimeter. (See FIG. 31)

3) The placement of a sensor (or set of sensors or integrated sensorysystem) on a central device, which detects and provides positioninformation of one or more robots, robot-enabled devices and/or otherdevices and relays that information and/or sends commands back to one ormore robots or robotic-enabled devices, which may or may not emit asignal or signals that help the sensor determine their position.

4) The placement of a sensor (or set of sensors or integrated sensorysystem) among one or more independent devices, where the data from thesensor(s) is relayed to one or more robots, robotic-enabled devicesand/or other devices.

5) Any combination of the above approaches—or other method for readingand reporting position information and/or identification of robots,robotic-enabled devices and/or other devices.

6) Any use of the above approaches, with the added integration of a3^(rd) party platform or device, such as a video game system (e.g.Nintendo® Wii®, X-Box 360®, Play Station 3®, etc.), handheld game system(PSP, Nintendo®DS®, etc), mobile phone, smart phone, PDA, mp3 device,television, computer, or Internet enabled game system (e.g. onlinegames), to help incorporate the position information, identify devices,transfer information, provide calculations, plan paths, monitor taskperformance and completion, pass information gathered from one operationto a later operation, update reference data sets and/or behaviors,enable user interface, and/or otherwise assist in operations related tothe localization of one or more robot and/or robotic enabled devices.

The sensor or sensors used by the localization system may be anycomponent, set of components or integrated system that help provide theidentification and/or any related position information of the variousgame objects. These sensor components and systems can include but arenot limited to: infrared sensors; cameras, imagers and/or other visualsensors; laser range finders or other laser sensors, infrared detectorsand/or emitters; wheel encoders or other odemetery sensors; opticalnavigation sensors; accelerometers, tilt sensors, gyroscopes, or otherposition and/or inertial sensors; thermal sensors; motion sensors;microphones, ultrasonic sensors and/or other sound sensors; RFID sensorsand/or other radio sensors; contact sensors; proximity sensors; magneticsensors; electrical field sensors; and/or any combination thereof. Thesystem may take the raw reading from the sensors and/or involveprocessing of the raw sensor values either as part of the sensingdevice, as part of another processing device, or as a combination ofprocesses.

Devices and/or objects can be designed to provide means for the sensorsto detect them, through active and/or passive methods, as part of thelocalization system. Active methods can include but are not limited tothe placement of beacons on one or more devices that emit a signal thesensors can detect and use to derive the identification and/or relativeposition information of the object. Beacons can include but are notlimited to: infrared light emitters, infrared spot projectors, othervisible or non-visible light emitters, laser emitters, thermal emitters,sound and sound wave emitters, motion emitters or devices that controlthe motion of objects, RFID or other radio emitters, magnetic emitters,electric field emitters, or any combination thereof. Passive methods caninvolve any approach where the sensors can detect one ore more object ordevices without the need for a signal to originate from the object ordevice. These methods can include but are not limited to visualrecognition of one or more objects or devices or a pattern on theobject, reflected light detection of the object, recognition of thephysical shape or construction of the object, recognition of motion ofthe object, or any combination thereof.

Additional examples of such and other embodiments, techniques and/orapplications for employing a localization system may be found inEvolution Robotics' application for U.S. patent application Ser. No.12/234,543, filed Sep. 19, 2008, which is hereby incorporated byreference herein.

The use of localization system to enhance the performance andcapabilities of a robot or robotic-enabled device in tasks such as floorcare and other localization-related applications as described earlierincludes but are not limited to:

1) The ability to use position information to clean a floorsystematically by controlling the location and/or path of a robot;executing coverage and/or cleaning patterns relative to the floorsurface to ensure good and even coverage; executing customized coverageand/or cleaning patterns relative to the floor surface based on userinput; optimizing coverage and/or cleaning patterns adapted toenvironmental conditions, the location of obstacles, different types offloor surfaces (e.g. carpeting vs. hardwood vs. tile, etc.) and/or otherlocation specific information; keeping track of cleaned and un-cleanedareas and/or explored and unexplored areas; and/or a combination of theabove methods. Embodiments of coverage and cleaning patterns usingposition information can include but are not limited to:

a) Paths involving one or more rectilinear patterns, which could includebut are not limited to where a robot cleans as it travels in a row-likepattern from one side of the room to the other (see FIG. 29), and/orwhere the robot cleans and travels in a row-like pattern in from oneside of the room to the other and then crosses back in a second row-likepattern perpendicular to the first (FIG. 30), and/or where a robotcleans by combining an overall rectilinear path with othernon-rectilinear motions. FIG. 29 illustrates a single pass parallel rowcleaning pattern according to an embodiment of the invention. FIG. 30illustrates a double-pass cross-row cleaning pattern according to anembodiment of the invention.

b) Cases where a robot cleans with a contour-following method using thewalls and/or edge of a room (and/or other objects and boundaries) tohelp define its path and engages in systematic adjustments in navigationto cover the floor surface, where one embodiment can include but is notlimited to driving parallel to the edges of a room and/or objects andshifting some distance inward upon the completion of each completed lapuntil it reaches the center of the area or the closest it can get to thecenter of the area. (FIG. 31). FIG. 31 illustrates a contour followingcleaning pattern according to an embodiment of the invention.

c) Cases where a robot cleans a room in smaller sub-sections, using oneor more systematic “micro” patterns to clean within a section, where asection can be defined by physical boundaries, virtual boundaries, userdefined boundaries and/or boundaries that adapt to the environmentalconditions, and then replicates that pattern on other sections until allof the open areas of the floor is reached using a “macro” pattern todefine and/or navigate between the subsections. (FIG. 32). FIG. 32illustrates a combination of macro and micro cleaning patterns accordingto an embodiment of the invention.

d) Cases where the robot follows an overall row-like, spiral or otherpattern to its path as it cleans but executes a variety of smallerpatterns within each segment of the path to provide deeper cleaning withmultiple passes along the path. (FIG. 33). FIG. 33 illustrates a deepcleaning pattern with a systematic path according to an embodiment ofthe invention.

e) Cases the robot cleans in a semi-random pattern in a specific sectionof the floor, but uses tracking of areas covered to intermittentlyrelocate its position to uncovered areas and/or stay within a certainboundary, and then moves onto new sections of the floor once its hasachieved adequate coverage, where one embodiment can include but is notlimited to applying avoidance behaviors to navigate away from coveredareas to probabilistically guide itself to uncovered areas (FIG. 34),and where another embodiment could include but not be limited to rapidactions where the robot's local movements can be fast and unpredictable,such as having the entire robot spin rapidly to buff, scrub or otherwiseclean the floor with rapid action. FIG. 34 illustrates a semi-randomcleaning with a system pattern according to an embodiment of theinvention.

f) Cases where the robot cleans using one of the above methods and/orother variations and completes by cleaning around the edges of the roomand/or around objects in the room.

g) Cases where the robot uses a cleaning pattern to consistently pushany remnant matter and/or fluid towards a specific area of the floor toconcentrate it one or more specific locations for user, the robot,and/or other device to collect. (FIG. 35). FIG. 35 illustrates acleaning pattern with a refreshing station according to an embodiment ofthe invention.

h) Cases where the robot follows one or more of the above cleaningmethods and/or other variations, but engages in multiple cycles where itvaries its activity for different stages in the cleaning process, suchas removing dirt first with one system and applying a protective finishwith a second system as just one embodiment; and/or any combination ofthe above approaches.

The ability for a robot and/or robots to clean with one of the abovemethods and/or other variations where the robot returns to one or morestations that allow it to refresh its cleaning mechanism (which mayinclude) but is not limited to:

1) unloading collected dirt, fluid, consumables and/or waste material,2) taking on new cleaning materials, fluids and/or consumables, and/orrecharging its batteries) and/or returns to clean where it last left offor continue to new areas as needed; the robot cleans with one of theabove methods and refreshes it owns cleaning mechanism(s) based on areacovered, time of operation and/or other means; and/or any combination ofthe above methods. One embodiment can be similar to the method exhibitedabove in FIG. 35.

2) The ability to use position information to navigate to one or morebase stations, with or without direct line of sight a base station, fromwithin the same room/zone and/or from outside of a room/zone, where therobot may or may not engage path planning techniques to developoptimized routes to one or more base stations. One embodiment caninclude but is not limited where a station includes a position signalemitter that enables the robot to automatically learn the physicallocation of the station and/or allow the robot to automaticallyrecalibrate the physical location of the station if the station is movedfrom its original point.

3) The ability to clean randomly or semi-randomly in areas whereposition information is not locally available, is only intermittentlyavailable and/or is less reliable, while being able to navigate back toan area where position information is available. (FIG. 36 exhibits oneembodiment where robot cleans under a table where position is notlocally available.) FIG. 36 illustrates a semi-random cleaning patternin areas where position information is limited according to anembodiment of the invention.

4) The ability to clean with some degree of systematic coverage in areaswhere position information is not locally available, is intermittentlyavailable and/or is less reliable, by making estimates of the positionof those areas by their boundary relative to one or more known areasand/or through the use of other measures or estimates of changes indistance, orientation and/or relative position from one or more knownpositions (such as but not limited to control of motors and/or wheels,feedback from motors, odometer readings, accelerometer readings, compasssensor readings, gyroscope sensor reading, proximity sensor readings,bump sensor readings, optical flow sensor reading, vision based sensorreadings, sonic based sensors readings, measurement of signal intensityof a faint, reflected and/or multipath signal, and/or other systems thatprovide indication of relative position.) In one embodiment related tothe scenario shown in FIG. 36, the robot can reacquire its positionanytime it emerges from beneath the table, and use that locationinformation to enhance the estimate of areas covered in the beneath thetable through the above methods.

5) The ability to use position information to travel from room-to-roomand/or zone-to-zone while maintaining abilities to clean the combinedarea systematically, where the robot may or may not engage path planningtechniques, mapping of obstacles and/or open areas, and/or user input onpaths to develop optimized routes between locations in different roomsand/or zones.

6) The ability to travel from room-to-room and/or zone-to-zone whereposition information may or may not be continuously available intransitional areas between rooms and/or zones, where the robot mayemploy one or more methods for transitioning in areas where positioninformation is not locally available, is intermittently available and/oris less reliable, by making estimates of the position of those areas bytheir boundary relative to one or more known areas and/or through theuse of other measures or estimates of changes in distance, orientationand/or relative position from one or more known positions (such as butnot limited to random and/or semi-random exploration, control of motorsand/or wheels, feedback from motors, odometer readings, accelerometerreadings, compass sensor readings, gyroscope sensor reading, proximitysensor readings, bump sensor readings, optical flow sensor reading,vision based sensor readings, sonic based sensors readings, measurementof signal intensity of a faint, reflected and/or multipath signal,and/or other systems that provide indication of relative position.)

7) The ability to expand the range of coverage and/or increase theaccuracy of the position estimate through the placement of one or moremobile devices to a known location that provides a secondary system ofone or more reference points for the robot to derive its relativeposition. One embodiment could include a system where the robot itselftemporarily places one or more mobile devices and/or objects at knownpositions, and uses those devices and/or objects to obtain and/orenhance position information for specific region, and may or may nothave the ability to retrieve the devices in order to repeat the processin additional areas.

8) The ability to use detection of the original source of one or moreemitted signals and/or reflections of one or more emitted signals tonavigate around obstacles and/or through open pathways (such as but notlimited to doorways, hallways, paths around furniture, etc.) wheredirect detection of the original emitted signal(s) may or may not beavailable and/or may not be strong enough to provide immediate and/orreliable absolute local position information.

9) The ability to use faint detection of one or more emitted signalsand/or reflections from far away from the originating point of one ormore signals in combination with exploring behaviors to progressivelymove toward areas where the signal(s) are stronger and/or eventuallyprogress to an area where the signals(s) are strong enough to acquirelocal position information.

10) The ability to use position information to enable users to trainand/or provide other inputs to the robot for helping define areas,paths, behaviors, priorities and/or techniques for cleaning, either byboundary, areas of focus (e.g. spot cleaning) specific paths to follow,patterns to execute, sequence of coverage, areas to avoid, and/or areasto ensure not to miss. One embodiment can include but is not limited toa device and/or configuration which enables the user to control themovement and/or other actions of the robot during the training period,where the robot records the positioning information and/or other userinput related to the desired cleaning behavior for those locations.Embodiments of this approach can include but are not limited to: apointing device that enables the user to direct the robot where to go,which may or may not include the means to input additional commands tothe robot that assign different cleaning behaviors for the location; adevice which the user to holds and/or wears that the robot can follow asthe user moves through the environment; a device that controls the robotwith an RF controller or other type remote control; a device thatremotely controls another mobile robot or device that the robot cantrack; and/or a configuration where the user manually moves the robotaround in the desired areas as it records its location and/or desiredcleaning behaviors. Another set of embodiments can involve devicesand/or configurations where the robot observes the movement of a seconddevice is that is manually or remotely controlled, and the robot recordsthe motion of the second device to learn location information forcleaning. The training for the above systems may or may not include amulti-room and/or multi-zone memory system, whereby the trainedinformation can be tied to specific rooms and/or zones, where the robotcan access the trained information when it detects and/or is instructedthat it is in a certain room/zone. Another set of embodiments caninclude but is not limited to physical placement of one or more devicesand/or object the robot can detect and integrate with its positioningsystem adapt its cleaning behavior, such as but not limited to devicesthat define a boundary, define a direction to follow, define an area toavoid, define an area to focus on for deeper cleaning, define an area touse a specific type of cleaning mode (such as steam cleaning only oncertain carpeted areas as just one possible example.)

11) The ability to use positioning information to have a robot learnareas through exploration where it tracks position information andintegrates learning of the environment (such as but not limited to:obstacle detection, types floor surfaces, areas of higher concentrationof dirt, pathways between areas, user input regarding the environment,and/or other means) to adapt its cleaning routines and/or otheroperations to optimize performance for that environment.

12) The ability to use positioning information to integrate user inputthrough the physical positioning of the robot to influence how the robotcleans and/or make cleaning more efficient and/or effective for aspecific area.

a) One embodiment can include but would not be limited to having theuser place the robot in corner of a room (such as the bottom rightcorner) as a starting point and combining that placement with a behaviorwhere the robot cleans from one corner to the other following a right toleft progression.

b) Another embodiment can include the user placing the robot in multiplelocations to train it on boundaries of the room, areas to cover, desiredstarting point and/or direction for cleaning, and/or patterns to use towhile cleaning.

13) The ability to integrate location identification connected to theposition information, such as input regarding the type of room it is in,such as a kitchen, dinner room, other type of room, to optimize whichbehavior(s) and/or algorithm(s) the robot selects to attempt to cleanthe room based on one more models of configurations and conditionslikely for that type of room.

a) One embodiment can be using the selection of a room ID of a NorthStarprojector (e.g. by its frequency or other means) to indicate the type ofroom, by which the NorthStar sensor on the robot is immediately awareupon detection of the signal and room ID. In that scenario, if forexample the room ID indicated the room was a dinning room, the robotcould select behavior(s) and/or algorithm(s) designed to detect thelocation of a primary table, pursue primary cleaning path around thefull perimeter of table, and engage routines for cleaning beneath thetable where it expects to come into contact with the legs of the tableand chairs.

14) The ability to have position information transferred from one deviceanother to optimize the performance of the system, through means whichcan include but is not limited to containing all or part of thelocalization system into a modular detachable device (such as a “roboticbrain”) that can be connected to a variety of robots, robotic-enableddevices and/or non-robotic devices, so that position information and/orother learning from the operation of the module in conjunction with oneor more robots, robotic-enabled devices and/or non-robotic devices canbe utilized when the module is later used in conjunction with anotherrobot or robotic-enabled device, as is described in TransferrableIntelligent Control Device, application Ser. No. 12/234,543, filed Sep.19, 2008, which is hereby incorporated by reference herein.

a) Another embodiment can include but is not limited to where the meansfor transforming information is primarily digital rather than physical,so that position information and/or other learning from the operationfrom one or more robots, robotic-enabled devices and/or non-roboticdevices can be shared by electronic means (such as through wiredcommunication, wireless communication, use of electronic data storagedevice, download through a computing platform, and/or other means) withother robots or robotic-enabled devices, in cases where the robots ordevices operate within the same environment but may or may not performsimilar tasks.

b) Another embodiment could involve the same approach described above,but where the learning is not limited to a specific environment, but mayprovide for more generalized leaning and/or application oflocalization-related behaviors across multiple robots and roboticsenabled devices in different environments, by abstracting descriptionsof environments and identifying which behaviors or combination ofbehaviors performed most successfully and/or predicting which behaviorsmay best perform given the new environment, specific robot orrobotic-enabled device platform, desired user goals, and/or othersituational conditions. Description of this technique is disclosed inU.S. Pat. No. 6,889,118, issued May 3, 2005, which is herebyincorporated by reference herein.

17) The ability to use position information and/or one or more of theabilities described above to coordinate behavior across two or morerobots and/or cooperatively perform one or more tasks, which can includebut is not limited to designating specific tasks for each robot,designating areas for each robot, and/or sharing information of tasksperformed and/or areas covered in order to have the robots operate as anintegrated system rather than independent devices.

FIG. 37 illustrates embodiments of a robotic cleaner according to anembodiment of the invention which includes a cleaning pad that can holda cleaning cloth, but in different form factor and shell configuration.The pad is extended out forward from the wheels and the design allowsfor a much larger robot body relative to the size of the cleaning pad.In an embodiment on this invention, the extra volume within the shellmay house additional cleaning mechanisms, which may include a vacuumthat uses the cleaning pad as an intake nozzle. The cleaning cloth maycover part of all of the vacuum intake area under the cleaning pad, sothat dirt is drawn into the cleaning cloth as a filter to add additionalability to remove dust, dirt, and debris from the floor. In models ofthe robotic cleaner, the robot may or may not have an internal dust binfor collecting the dirt based on whether the design allows for dirt toget past the cleaning pad.

FIG. 38 and FIG. 46 illustrate various embodiments of a robotic cleaneraccording to embodiment of the invention which use a horizontal rotatingbrush as part of the cleaning mechanism. The robotic cleaner may includea collection bin behind the brush for collecting dust, dirt and debris.The brush may be removable, either as a single component, or in two ormore sections. The brush may be disposable. The brush may be composed ofa non-woven material (similar to the material in the cleaning clothsdescribed in other embodiments) or other type of material that collectsdirt and dust on the brush itself as part of the cleaning function.

FIG. 39 and FIG. 40 illustrate embodiments of a robotic cleaneraccording to an embodiment of the invention which include a loadabletray for holding multiple cleaning cloths, cleaning pads, or othermaterial. The assembly in the drawings is integrated with a robot thatincludes a roller brush at the opposite end of the robot, but themechanism may be used with other robot bodies. The cleaning cloth may beloaded into the robot in a variety of ways, which include but are notlimited to loading the cleaning cloths or cleaning pads into the top ofthe loadable tray, or opening a cover over the loadable tray will allowsthe user to place the cleaning cloths or cleaning pads in the tray. Inmodels of the robotic cleaner, dirty or used cleaning cloths andcleaning pads may be manually removed by the user, such as by pullingthe bottom cleaning cloth or cleaning pad out from the side of theloadable tray, or pulling the cleaning cloth or cleaning pad out fromthe bottom of the robot, leaving a clean and fresh cleaning cloth orcleaning pad exposed and ready for use. In models of the roboticcleaner, a docking station for the robot may be available which therobot can automatically dock with, where the entry point for the robotinto the docking station includes directional teeth or some type ofgripping surface, where by the bottom cleaning pad is pulled off fromthe robot as the robot backs out of the dock, thus providing a means forautomatically removing the cleaning cloth or cleaning pad.

FIG. 41 illustrates embodiments of a robotic cleaner according to anembodiment of the invention which include a vacuum and collection bin invarious configurations. A cleaning pad is included in the design toprovide behind the intake area of the vacuum to allow the pad to pick updust, dirt and debris that the vacuum may have missed. In models of therobotic cleaner, the height of the robot may be extended to provide morespace for the vacuum system, battery and bin space to provide bettervacuum strength and or debris capacity. In models of the roboticcleaner, the collection bin is transparent to allow the user to easilysee when the robot is reaching its maximum holding capacity and needsthe bin needs to be emptied, without requiring the user to manually openand or remove the bin to check its status.

FIG. 42, FIG. 44, and FIG. 47 illustrate various embodiments of arobotic cleaner according to embodiment of the invention which use oneor more vertically oriented scrubbing brushes mounted along the exteriorof the robot. The robotic cleaner may include a bin for storing cleaningfluid which the robot dispenses for use with the scrubbing brush. Therobotic cleaner may include a second container bin for storing spentcleaning fluid and dirt that has been taken up from the floor by anothermechanism on the robot. In models of the robotic cleaner, differentconfigurations of the brush and floor solutions may be used, such ashaving one brush scrub and one brush or rotating pad buff the floor. Inmodels of the robotic cleaner, different solutions may be dispensedwithin or near the different brush mechanisms, such as a cleaningsolution near the scrubbing brush and a waxing solution need the buffingbrush or pad.

FIG. 43 illustrates embodiments of a robotic cleaner according to anembodiment of the invention which includes a horizontally orientedrotating brush with a spraying nozzle above the brush that dispensescleaning fluid in the area in front of the brush. Models of this roboticcleaner may be programmed to drive to a certain point, and then backaway a fixed distance before spraying to ensure the robot does not sprayonto a wall or other surface of the floor, such as carpeting, which isnear the cleaning area.

FIG. 45 illustrates an embodiment of a robotic cleaner according to anembodiment of the invention where the robot is in a circular form andincludes a vertically oriented circular brush that extends to the outerof perimeter of the robot as a ring and spins around the robot's centeraxis. To maximize the reach of the brush, the wheels and othermechanisms of the robot are placed within the ring of the brush. Inmodels of the robotic cleaner, the brush may be exposed at all sideedges, partially exposed as shown in FIG. 45, such as in the front ofthe robot, or fully covered by the shell of the robot. In models of therobotic cleaner, counter rotating brushes may be used, where one or morebrushes are nested within the ring of another brush that travels in anopposite direction. In models of the robotic cleaner where part of thebrush is exposed at the sides of the robot, the brushes may be angled insuch away that they extend past the perimeter of the exterior robotshell and area able to make contact with side obstacles and walls toprovide for side surface cleaning in addition to floor surface cleaning.

FIG. 47 illustrates embodiments of a robotic cleaner according to anembodiment of the invention in different configurations with exteriormounted vertically oriented scrubbing brushes. In models of the roboticcleaner, one or more of the scrubbing brush units may be detachable fromthe main robot body for independent use. This may include where thedetachable brush unit has its own rechargeable battery which powers thebrush function while detached from the main robot body. The batteries inthe detachable brush unit may be able to charge from the main robot whenconnected to the main robot body, as well as may be able to be utilizedby the main robot's power system when connected to the main robot body.A control interface between the detachable brush unit and the main robotbody may allow the main robot to control the functions of the detachablebrush unit while connected. In models of the robotic cleaner, thedetachable brush may be designed for manual use, such as a hand heldpowered brush. In models of the robotic cleaner, the detachable brushunit may have its own control system for autonomous operation. Tosupport autonomous operation, the detachable brush unit may also haveits own means for locomotion, which may include but are not limited to:using the rotation of the cleaning brush to move the brush unit, usingwheels nested within the cleaning brush unit to move and control thebrush unit, and/or a combination of the two methods. In models of therobotic cleaner, the main robot body may emit a signal or set of signalsthat enable the detachable brush unit to navigate away from and returnfrom the main robot body to detach and re-attached autonomously. Inmodels of the robotic cleaner, the detachable brush unit may emit asignal or set of signals that enable the main robot body to determinethe relative location of the detachable brush unit and remotely sendcommands to control the movement of the detachable brush unit. Inalternative embodiments of the invention, similar systems may be usedfor a main robot to control one or more remote cleaning devices whichmay be configured with a variety of cleaning functions.

FIG. 37 illustrates embodiments of a robotic cleaner according to anembodiment of the invention which includes a cleaning pad that can holda cleaning cloth, The vacuum hose may be mounted on the exterior of therobot, leading up to a forward air intake that is flush with the floorsurface. Multiple hoses may be used to provide more even distribution ofthe suction over a cross section of the air intake. A cleaning pad,cleaning cloth or other cleaning material may or may not be used incombination with the vacuum function.

The invention may be implemented in hardware or software, or acombination of both (e.g., programmable logic arrays). Unless otherwisespecified, the algorithms included as part of the invention are notinherently related to any particular computer or other apparatus. Inparticular, various general purpose machines may be used with programswritten in accordance with the teachings herein, or it may be moreconvenient to construct more specialized apparatus (e.g., integratedcircuits) to perform particular functions. Thus, the invention may beimplemented in one or more computer programs executing on one or moreprogrammable computer systems each comprising at least one processor, atleast one data storage system (which may include volatile andnon-volatile memory and/or storage elements), at least one input deviceor port, and at least one output device or port. Program code is appliedto input data to perform the functions described herein and generateoutput information. The output information is applied to one or moreoutput devices, in known fashion.

Each such program may be implemented in any desired computer language(including machine, assembly, or high level procedural, logical, orobject oriented programming languages) to communicate with a computersystem. In any case, the language may be a compiled or interpretedlanguage.

Each such computer program is preferably stored on or downloaded to astorage media or device (e.g., solid state memory or media, or magneticor optical media) readable by a general or special purpose programmablecomputer, for configuring and operating the computer when the storagemedia or device is read by the computer system to perform the proceduresdescribed herein. The inventive system may also be considered to beimplemented as a computer-readable storage medium, configured with acomputer program, where the storage medium so configured causes acomputer system to operate in a specific and predefined manner toperform the functions described herein.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, some of the steps described above may be order independent, andthus can be performed in an order different from that described.Accordingly, other embodiments are within the scope of the followingclaims.

1-28. (canceled)
 29. A robotic cleaner, comprising: a motorized driveassembly comprising two wheels and configured to move the roboticcleaner, the two wheels configured to rotate about a first axis that issubstantially perpendicular to a forward direction of travel of therobotic cleaner; a microcontroller operatively coupled to the motorizeddrive assembly for controlling movement of the robotic cleaner; acleaning assembly configured to clean a floor surface, the cleaningassembly configured to hold a cleaning cloth, the cleaning assemblybeing positioned along a second axis substantially parallel to and aheadof the first axis in the forward direction of travel of the roboticcleaner; a holding tank configured to hold a cleaning solution, whereinthe robotic cleaner is configured to spray the cleaning solution ontothe floor surface with a sprayer; and charging contacts for charging abattery onboard the robotic cleaner, the charging contacts configured toengage charging connections of a charging docking station, the chargingcontacts being positioned behind the first axis and the second axis. 30.The robotic cleaner of claim 29, wherein the charging contacts arepositioned along a third axis substantially parallel to and behind thefirst axis.
 31. The robotic cleaner of claim 29, wherein the chargingcontacts are positioned on a bottom portion of the robotic cleaner. 32.The robotic cleaner of claim 29, further comprising at least one sensorconfigured to cause the robotic cleaner to drive onto a docking ramp ofthe charging docking station and stop over a pattern on the dockingramp.
 33. The robotic cleaner of claim 29, further comprising an opticalnavigation sensor positioned on a top portion of the robotic cleaner fordetecting an alignment beacon signal emitted from the charging dockingstation.
 34. The robotic cleaner of claim 29, wherein themicrocontroller is configured to cause the robotic cleaner to back ontothe charging docking station.
 35. The robotic cleaner of claim 29,wherein the cleaning cloth is removably coupled to the cleaning assemblyfor removal from the cleaning assembly upon the robotic cleanerundocking from the charging docking station.
 36. The robotic cleaner ofclaim 29, further comprising a bump sensor positioned to extend along afront edge of the robotic cleaner, wherein the bump sensor is configuredto detect a contact at a point on the front edge of the robotic cleanerwhile the robotic cleaner is being directed to move in the forwarddirection of travel.
 37. The robotic cleaner of claim 29, wherein thesprayer is a forward spraying jet that dispenses the cleaning solutionin an area in front of the robotic cleaner.
 38. The robotic cleaner ofclaim 29, wherein the microcontroller is configured to drive the roboticcleaner to a point, and then back away a fixed distance before sprayingthe cleaning solution.
 39. The robotic cleaner of claim 29, furthercomprising a sensor configured to detect a collision of the roboticcleaner with an overhanging obstacle, wherein the microcontroller isconfigured to reverse the direction of travel of the robotic cleaner inresponse to the sensor detecting the collision with the overhangingobstacle.
 40. A robotic cleaner kit comprising: a charging dockingstation comprising: a plug, and charging connections connected to theplug for recharging a rechargeable battery; and a robotic cleaner,comprising: a motorized drive assembly comprising two wheels andconfigured to move the robotic cleaner, the two wheels configured torotate about a first axis that is substantially perpendicular to aforward direction of travel of the robotic cleaner, a microcontrolleroperatively coupled to the motorized drive assembly for controllingmovement of the robotic cleaner, a cleaning assembly configured to cleana floor surface, the cleaning assembly configured to hold a cleaningcloth, the cleaning assembly being positioned along a second axissubstantially parallel to and ahead of the first axis in the forwarddirection of travel of the robotic cleaner, a holding tank configured tohold a cleaning solution, wherein the robotic cleaner is configured tospray the cleaning solution onto the floor surface with a sprayer, andcharging contacts for charging a battery onboard the robotic cleaner,the charging contacts configured to engage the charging connections ofthe charging docking station, the charging contacts being positionedbehind the first axis and the second axis.
 41. The robotic cleaner kitof claim 40, wherein the charging docking station comprises a newcleaning cloth storage well.
 42. The robotic cleaner kit of claim 40,wherein the charging docking station comprises an emitter for emittingan alignment beacon signal and wherein the robotic cleaner comprises anoptical navigation sensor positioned on a top portion of the roboticcleaner for detecting the alignment beacon signal emitted from theemitter.
 43. The robotic cleaner kit of claim 42, wherein themicrocontroller is configured to cause the robotic cleaner to back intothe charging docking station in response to the optical navigationsensor detecting the alignment beacon signal emitted from the emitter.44. The robotic cleaner kit of claim 40, wherein the charging dockingstation includes a ramp portion.
 45. The robotic cleaner kit of claim40, where the charging docking station includes an area marked with apattern, wherein the robotic cleaner includes at least one sensorconfigured to cause the robotic cleaner to drive onto a docking ramp ofthe charging docking station and stop over the area marked with thepattern.
 46. The robotic cleaner kit of claim 40, wherein the chargingdocking station comprises a cleaning cloth catch for removing a cleaningcloth from the robotic cleaner.